Tsukune Aono is the main male protagonist of the anime/manga series Rosario + Vampire. He is a human teenager who is mistakenly enrolled in an academy for monsters, where he meets Moka Akashiya, a vampire who takes an interest in him and the sweet flavor of his blood. Despite liking Moka (average), Tsukune soon encounters Kurumu Kurono, Yukari Sendo,Ruby Tōjō, and Mizore Shirayuki, all of whom develop feelings for him and become his closest friends. Along with his unwanted harem, Tsukune also makes a few male friends and acquaintances as well: Ginei Morioka, Fang Fang Huang, and Hokuto Kaneshiro.
Tsukune is later injected with Moka's vampire blood transforming into a Ghoul and undergoes several major bodily changes, including the Human Modification Ritual, emerging as a Modified Human and possessing both yōjutsu and vampiric powers. Later on, Tsukune finally gains full control over his vampiric powers and becomes a Shinso Vampire.
He is voiced by Daisuke Kishio in the Japanese version of the anime and Todd Haberkorn in the English version, the former of whom also voices Loke.
Tsukune’s typical appearance is that of an average human teenager: he has black hair, brown eyes and a relatively athletic physique. Whenever he is injected with some of Moka’s blood, his eyes develop slitted pupils, much like those a true vampire when they exert their power. After becoming a modified human, blue patterns that resemble the conductive tracks of a printed circuit board appear on Tsukune’s skin when using his newly-learned spells and powers. His eyes also appear to change from brown to blue when using certain Youjutsu techniques. The wounds he often sustains from altercations with monsters leave several scars on his body, the most prominent being an X-shaped mark on his torso he received from a monstrel that possessed blades for arms.
During his initial transformation into a ghoul, he develops the aforementioned vampiric eyes in addition to a black, web-shaped mark on his neck and face, originating from the puncture marks made by Moka’s fangs. When he experiences a complete—albeit temporary—transformation into a ghoul during his human modification ritual, he gains silver hair, empty white eyes, fangs and bat-like wings. His skin also turns mostly black with red patches over some of his muscles and crack-like patterns on his face, arms and torso. After undoing the first and second seal of his Holy Lock while aboard the Hanging Garden, Tsukune’s third transformation into a ghoul is slow but obvious: a black layer of skin gradually spreads over his body, wings begin to sprout from his back and parts of his body, such as his right arm, sporadically mutate due to being in close proximity to an awakening Alucard, the Shinso blood of whom having been directly passed onto him by Moka and her mother interacting with the supernatural energy of its original owner through his body.
After tearing off his Holy Lock to become a Shinso vampire to and learning how to control his new abilities with his friends’ aid, Tsukune can use his now immense Wealth of Power to change his physical appearance. He can now make his black hair silver, his round pupils slitted and create a black layer of skin that covers most of his body save for his face. This greater access to his aura allows him to sprout large bat-like wings from his back and likely make a full transformation into a rat or bat. He can also use his Creation ability to form a suit of flexible steel armor around his upper body, protecting him from injury to a certain extent.
For most of the series, Tsukune has worn the traditional Yokai Academy uniform with little personal modification: a white button-up shirt, a red tie, a green jacket, a black belt, light brown khakis and dark loafers. In the anime, he has occasionally worn uwabaki slippers with green soles. After the battle with Alucard at the end of the manga, he abandons the jacket of his uniform entirely. His casual attire consists of a green button-up shirt, a white T-shirt, a black belt, brown cargo pants and white sneakers. At the beach, he is shown to wear dark blue swimming trunks and sandals.
It should be noted that Tsukune is perhaps the most decent, chivalrous and compassionate character in the entire series. During his time at Yokai Academy, he comes to see monsters as equals and share the hope that they can live peacefully alongside humans. Despite there being many instances where he has been put into dangerous, even life-threatening situations, he is seemingly unable to bear hatred or hold a grudge and has forgiven those who have previously tried to do him harm. His selflessness and courage often comes out when he or someone from his group of friends is faced with the possibility of injury or even death. He is also willing to sacrifice anything order to protect the people he holds dear, even his own humanity. This is what has ultimately gained him friends at the academy as well as the affections of Moka, Kurumu, Mizore, Ruby and Yukari.
Although Tsukune is willing to do battle when necessary, as an idealist who strives for peace, he favors diplomacy over violence. He has expressed his desire to simply reason with some monsters such as Lady Oyakata and Gyokuro Shuzen rather than fight them. While he has certainly regarded many of his encountered enemies with anger, he does not appear to truly wish them ill will or death. This is not without exceptions, though: he butchered some the ghouls of the Black Parade before confronting Gyokuro, an act that, when one considers the fact that they were once vampires who had been turned into mindless creatures, can be viewed a kind of mercy-killing. Before that, he verbally threatened Kuyou’s life during their rematch, though this was likely a side-effect of Tsukune’s own ghoulish nature surfacing after removing the first seal of his Holy Lock. The use of his Creation ability to nearly obliterate Alucard’s body conveys lethal intent as well, which is not at all unjustified given that Alucard was too large and resilient to be damaged by much else.
Even though there have been many instances, where he has been put into dangerous, life-threatening situations (many of which are due to enemies whom he later befriends), he has never held a grudge against anyone. Tsukune's selflessness and courage comes to the foreground, whenever he or someone from his group of friends is faced with the possibility of injury, or even death. Though powerless, he has the tendency of throwing himself into danger to ensure the safety of his friends. As the series progresses, this habit becomes extremely dangerous the enemies he encounters are so powerful that he frequently comes close to dying. Ironically, this leads to a situation where he calls upon "his own" supernatural abilities (originally from Inner Moka) as well as the concealment of his human identity from much of the student body.
Even after becoming a vampire, Tsukune has not changed as a person. He considers himself as much a human on the inside as he once was outside. To him, what he is does not matter so long as his personality remains intact and he can protect and be with the people he cares about, especially Moka.
As a human, Tsukune used to rely on his ability to take off Moka's Rosario Cross, releasing her true vampire state, and have her fend off opponents. Thus far, he is the only one who can successfully do so because he truly and unconditionally loves Moka and wishes her no harm, causing her Rosario to accept him.Modified Human Physiology & Vampirism: Due to repeated vampire blood transfusions from Moka, Tsukune gained powers and abilities vastly exceeding those of a human being and arguably most vampires. After his final transfusion he had become vampiric ghoul with abilities surpassing a normal vampire at the cost of his insanity. Finally, thanks to Touhou Fuhai, who modified his body, Tsukune became able to use Yōjutsu techniques. As a Shinso vampire, Tsukune can rely on his own latent powers to fight.
- Immense Speed: As a ghoul, Tsukune's speed has been repeatedly shown to be beyond the standards of high level monsters, including speed specialized ones, much less normal humans. Following his training under Moka, his speed was raised enough in his human form to defeat a group of human gangsters, despite being armed with guns. After his modification and training with Tohou Fuhai, he managed to defeat Kuyou by passing his flames before the heat could affect him and later evade some of Akua Shuzen's attacks, who was noted for her reflexes, evading her and catching Moka in an embrace. Following the release of his first seal, his speed increased to the point he was able to bypass Kuyō and take him down before Kuyō could make his own attack as well as pressure Akua into defending herself, which left her open to Moka's own attack. Upon unlocking his second seal, Tsukune was able to kill most if not all of the mutated ghouls of Gyokuro's Black Parade in seconds and managed to slip inside Gyokuro Shuzen's guard and wound her at her right shoulder before she could react. During their fight, Tsukune was able to keep Gyokuro pressured and cornered before she resorted to releasing her seal to increase her power. After becoming a Shinso Vampire, he was able to instantly destroy Alucard's body alongside Moka.
- Immense Strength: Tsukune has gained enough raw strength to defeat even high level monsters, such as Kuyō, in a single strike. As a result of this ease, it is also sometimes hard to grasp the actual limits to his physical strength. In his fully transformed ghoul form which is that of a jet black monster, Tsukune's strength became so overwhelming that even Touhou Fuhai barely survived after taking a single blow from him, albeit he was in a weakened state at the time. After his body modification, it is shown that Tsukune is now strong enough in human form to catch a giant pillar with his bare hands, even when it was thrown at him by the likes of Gyokuro Shuzen. After releasing the second seal on his holy lock, he proved strong enough to completely pulverize the ground Gyokuro was standing on and temporarily overwhelm her during their fight, even after she removed her limiter to increase her power. She observed that he was on par with Alucard, potential-wise, at least. After becoming a Shinso, Tsukune's strength becomes stabilized and controllable and was able to easily destroy Alucard's body with simple punches alone.
- Immense Agility: Tsukune's agility is enhanced to superhuman levels well beyond even the finest human athletes, and can easily swing and jump from one building's roof to another during battle.
- Immense Reflexes: Tsukune's reflexes are enhanced beyond the human limits. When fighting enemies that are less powerful than vampires, they seem to move in slow motion compared to him, allowing him to quickly counter. Repeatedly, Tsukune has been shown to catch his enemy before they strike him, usually right as he enters the transformed state, and then strike back. Following the release of his first seal, Akua had trouble striking him during their fight, but Tsukune also has trouble striking Akua due to his lack of experience in regards to her more often then not made up for this advantage. Upon unlocking his second seal, Tsukune's reflexes increase to a greater point where he was able to match Gyokuro as an opponent and temporarily best her until his mutation began to hinder him.
- Immense Durability: The tissues and bones of his body are considerably stronger and more resistant to physical injury than those of ordinary humans and powerful monsters. This is evident even before his body reconstruction as he endured several water bullet attacks and sound based attacks with very little harm compared to his friends, all of whom are powerful monsters in their own right. He competed with Kuyō on equal footing and came out of the battle fairly unscathed. He took a sneak attack from Gyokuro straight to his face without dying, an attack from Hokuto that was aimed to kill Moka and in both cases recovered ominously fast. When transformed into a Ghoul, his endurance works in conjunction with his regenerative abilities and results in an almost unstoppable creature. Ultimately, even Gyokuro Shuzen, who delivered twice as many blows as she received, still fell before Tsukune himself did during their fight when it erupted into a mere punch up, even though he fought Kuyou and Akua before in sequence. Even after receiving a crippling punch in his stomach from Miyabi, Tsukune was still able to get back in the battle and shield Moka by allowing himself to get pierced several times by Alucard's tentacles. Later in his final form as a Shinso Vampire, Tsukune is able to remain conscious after being impaled by another one of Alucard's tentacles through his lower torso, though he is weakened and has trouble standing for a brief time.
- Immense Stamina: Tsukune's training from Inner Moka has resulted in a musculature that produces considerably less fatigue toxins during physical activity than that of an ordinary human, allowing him to be physically active for longer periods of time. He has managed to fight Kuyou, Akua and Gyokuro in rapid succession while suffering from only a less than moderate state fatigue. Whatever form he is in, his willpower seems to have some influence on this stamina.
- Yoki Detection: Tsukune is granted this ability by the vampire blood inside him. After being taught to use this ability by Inner Moka, he is able to sense the demonic aura of other monsters. Later on, Tsukune is shown to use this ability more effectively, as demonstrated when he was able to sense a pitch-black aura being emitted from someone in the Floating Garden, later determining that this aura was in fact being emitted from Gyokuro Shuzen. Later, it is shown that Tsukune is not always able to sense other monsters, as shown by his ignorance to an invisible monster that would have killed him with poison had he not been saved by Issa Shuzen, who could apparently detect the creature's presence.
- High-Speed Regeneration: Tsukune has the ability to regenerate at an astonishing rate. After he was mortally wounded during his fight with Midou Kusabi, Tsukune received the final injection of Moka's vampire blood and transformed into a Ghoul. Within moments, his gaping wounds and lacerations began sealing themselves up, much to Midou's surprise and Inner Moka's curiosity. When in his vampire and ghoul forms, respectively, Tsukune's healing powers undergo a proportionate increase, with the latter surviving multiple heavy attacks from Moka and recovering. To some extent, his human form also seems to have a higher level of regeneration than that of a regular human, as he heals far quicker from fatigue or injury than any human being of average health and conditioning would be expected to. This includes receiving a punch from Gyokuro which sent him flying and then being nearly eaten by Alucard, after which he recovered, unassisted and treated, within a few minutes and returned to the battle. Immediately following Gyokuro's initial defeat, during which he received many heavy attacks and a visibly painful set of mutations to his person, Tsukune shrugged it off through willpower and prepared to stand beside his friends to face the Alucard-empowered Gyokuro. As a Shinso, Tsukune is shown to be able to survive and—in anywhere from seconds to minutes—heal from grievous injuries that would normally kill most living things, such as being impaled by one of Alucard's tentacles. If he is anything like other Shinsos, he can probably survive having a limb or his lower torso severed and have such body parts reattach themselves in seconds, provided he does so in time to avoid bleeding to death.
- Shinso Bloodline: Tsukune has inherited the blood of three Shinso vampires which belonged to Akasha, Alucard and Moka. This blood is corrupted as it also includes a mix of all the blood Alucard had absorbed in the past, granting him a legendary power far greater than any average vampires. The blood was given to him through multiple injections from Moka causing Tsukune's features to change to the tell-tall characteristics of the legendary Shinso vampire, however, this can also result in uncontrollable mutations since the blood propagates inside the host causing the body to change and like Moka it's also the key to reviving the monstrous vampire Alucard but unlike Moka, Tsukune does not possess a seal to prevent Alucard from awakening, but this will only happen if he carelessly unleashes his Shinso power while being near Alucard's body. This also works in vice versa if Alucard is revived causing Tsukune to resonate with the monster and mutate uncontrollably. Touhou Fuhai states that he is one of the successors of the Shinso. Later on, Tsukune eventually transforms into a Shinso vampire after inheriting this bloodline.
- Immense Demonic Aura: Tsukune's Shinso blood has given him tremendous Yōki that is described as "a darkness deeper than night". When Tsukune utilizes his vampiric powers he radiates a much darker, more potent aura than the usual vampire blood. After his modification and training with Touhou Fuhai, Tsukune can release an aura that terrified even the arrogant Kuyō after entering his vampire form. Upon defeating Kuyō, Tsukune's energy depicted a visage of Alucard which Ruby (while terrified as well) notes to be far more sinister and horrifying than Kuyō could ever be. During his fight with Gyokuro after releasing his second seal, Tsukune emitted another visage of Alucard that briefly scared Gyokuro and also made her note that Tsukune is potentially on par with Alucard because of this power and that he is evolving into a being like Alucard.
- Blood Link: A unique ability Tsukune gained after permanently having Shinso flowing through his veins upon having his ghoul nature suppressed by the holy lock. This allows him sense when Moka, the one who gave him the Shinso blood, is feeling great emotional stress and vice versa.
- Creation: Akua states that the Shinso possess an ability called "Creation." By mixing Yōki into their own blood and controlling it at will, they can transform it into solid matter and mold it into anything they desire. In Tsukune's case he is able to generate a jet-black, steel suit of armor that covers his entire upper body and the sides of his face along with plated armor and shoulder pauldrons. He can also use this ability to make something explode just by hitting it hard enough.
- Blood Transfusion: Tsukune is able to use this ability by taking off the Holy Lock completely in order to become a true vampire to save and revive Moka by injecting his own blood. Now as a Shinso vampire, Tsukune has fully enhanced fangs to use this if he needs to.
- Wealth of Power: Yukari states that all Vampires have an ability called "Wealth of Power." Yukari also states that most vampires have rejected using this ability in spite of its tremendous potential due to their innate narcissism and vanity. When Tsukune's Shinso blood had gone out of control from the incomplete human modification technique casted by Touhou Fuhai, he grew giant bat wings used for flight in his jet black monster form before the modification was complete. After releasing his second seal, Tsukune's features transformed into half vampire and half ghoul and had incomplete bat wings growing out of him which is due to him having yet to become a true vampire at the time.
- Flight: After transforming into a Shinso vampire, Tsukune has gained the ability to grow giant bat wings from his upper back giving him flight capabilities. Tsukune originally displayed the ability of flight when he transformed into his jet black monster form when his Shinso blood had gone out of control during his modification.
- Human Origins: Given that Tsukune was originally human, he is unaffected by coming into contact with water and possibly many other things that vampires are weak against. He also exempt from the rule that prevents monsters from attacking humans, since he was once a human himself.