Takeda was once a successful boxer. He had a best friend who watched his back and the two would fight together. However one day, an incident occured when Takeda's friend was attacked by some thugs. Takeda came to help his friend but he recieved a serious injury to his left arm leaving it paralyzed. Takeda's friend left him behind to become famous. This caused Takeda to lose his love for fighting and become a delinquent. Later, he joined Ragnarok and met Ukita, his best friend.
Unlike the cowardly Kenichi Shirahama, Takeda rushes into battle full of confidence and has a very light hearted.
Like Kenichi, he is scared to train under James Shiba as his methods are just as cruel and brutal as Akisame's. He even shows fear and often wants to quit mainly for comical purposes. However, he highly respects his master and has never once questioned his training methods and was very glad to finally get praised by him for the first time after his fight with Lugh. He also seems rather scared when his master shows unusual kindness towards him, which he finds scarier than his training.attitude, joking even during serious situations. He also shows extreme respect for his master James Shiba and the Masters of Ryozanpaku. He is also passionate about Boxing and was a rising boxing star, but an incident where he came to the aid of his friend caused harm to his left arm, leaving it paralyzed, and him scornful. After his arm is fixed by Kōetsuji, Takeda regains his lighthearted personality and becomes more friendly, to the point where he stepped into the ring to challenge Member J of the Black Force team for the latter's disrespect towards Mizunuma. Takeda is shown to have a poor grasp of the English language, proclaiming to an enemy during the D of D tournament: "I AM WIN! YOU SAY SORRY! OK?", trying to get him to apologize to a member of the Shinpaku Alliance if he were to beat him in the fight. Since he and Ukita were delinquents throughout their last year of high school, they were forced to repeat another year.
He, like many characters in the series, has feelings towards Miu, as he always calls her "Honey". His affection goes largely unadressed throughout the series as he also tries to protect her, such as refusing to give up in a battle against Sho Kanou, during which he states she's "the friend of the person who saved his life". He even said to Kenichi that should Takeda win the match, he would confess his true feelings towards her. After Takeda lost, he just said he was joking to get Kenichi to fight more seriously (though his actions towards her show otherwise). Also, during Yami Transport Data arc he wanted to give Miu his jacket to cover herself, but gave it to Kenichi and told him to give it to her which prove that he aprove their relationship. However, he was shown to release a bloodthirst when he know that they are alone at the dojo and the other are asking them of their progress. Recently, while he still cares for Miu very much, he seems to have taken a liking to Freya since the two were on a double date together and his master, James Shiba, believes they are a couple.Takeda has since viewed Kenichi as his savior and close friend for saving his life and fixing his arm. It is because of him that he turned his life around and has become so much stronger. He always has Kenichi's back and will follow his lead without fear or question, showing great loyalty. He respects Kenichi to the point of allowing him to be with Miu out of respect for saving his life. He is best friends with Ukita. They have always hung out together and watched each others backs in any fight or situation they are involved in. The two are so close that they even ended up being forced to repeat another year of school due to their friendship.
Takeda seems to not get along well with Natsu due to them having once been enemies and due to the fact that Natsu always seems to have a heavy Ki around him whenever Miu and Kenichi are talking to him. He also has a strong sense of humor, often laughing hysterically when something funny happens, such as when Ukita made a fool of himself in front of Kisara and again when Ukita mistook Shiratori's "doppleganger" as a female version of "him".
Despite never having a Master from the beginning, Takeda was a gifted rookie boxer with a promising potential future in the pro league. His high aptitude for boxing, combined with his great ambition and even higher tenacity for winning made him able to at least hold his own against seemingly any disciple-level opponent. As he changed his ways from a delinquent, he trained to increase his strength and skill to a point where he has nearly caught up with both Kenichi and Natsu in a short amount of time. He can also be seen as an opposite of Kenichi, as he focuses more on speed and agility than power and versatility. His extensive growth after gaining a true master to train him was revealed during his rematch with Kenichi, where he overwhelmed the younger opponent before being barely defeated. His performance even earned praise from Akisame, despite his own disciple battling Takeda in bet. As noted by Lugh, a highly perceptive fighter, Takeda will undoubtedly become a master-class in the future and that his progress has reached a point that he can fight on par with a YOMI. Takeda could fight Lugh, one of the strongest members of YOMI (if not second strongest as stated by Ogata Isshinsai) evenly and ultimately defeat him, something that even Ogata was surprised at.
- Expert Boxer: Even before receiving master training, Takeda was already considered to be a great enough boxer to make it to a professional level. After receiving training from a master, Takeda's boxing skills skyrocketed to new heights. He can now accurately block attacks from very versatile fighters like Kenichi using only his knuckles, fight evenly with fighters like Lugh, and even fight evenly against weapon users despite being at a great disadvantage against them being a boxer. Takeda is currently training in both inner and outer forms of boxing, and also learning advance techniques from the unique underground boxing style from James Shiba.
- Innate Talent: Takeda was a highly prized rookie boxer during his professional days. Even without the training of a master, he could take down heavyweight boxers. But, the point where his power and technique increased dramatically in just a short time was when he found himself under the wing of a famed underground-boxing master, James Shiba. His sense and talent in boxing even impressed prominent, highly skilled characters such as Akisame, Sho Kano, Ogata, Lugh, and even the Elder.
- Enhanced Strength: Takeda's physical power is strong enough that he can stop a wooden weapon user or a knee attack from Kenichi with just the knuckles of his hand. Using his skilled fists, his record remains undefeated in the underground martial arts arena. His strength has recently in his fight with Lugh grown to the point of being able to punch through a wall with only a few jabs.
- Enhanced Defense: Takeda uses precised blocks against any type of attack regardless if it's punches or kicks using just his fist. He can also defend against attacks using Tai Chi-like moves such as kakei where they shift the power of the attack away.
- Enhanced Endurance: Takeda has shown to be a highly durable fighter, being the only one of the main Shinpaku members when assalted by Sho, the former leader of YOMI, Takeda was the only one still conscious and capable of fighting. In his rematch fight with Kenichi, even after losing consciousness, he was still able to fight by reflexes thanks to his master. Even after having his left pinky broken and right leg dislocated, he was able to snap it back into place and fight like it hardly affected him. He managed to later overwhelm Lugh in there second fight after having his hands bleed from the mirror house and counterattack from the blood loss and eventually defeat the submission man. He is able to take one of kenichi most powerful attacks like Mubyoshi combines with the techinque Ryusei Seikuken and get up after taking the hit.
- Enhanced Speed: Takeda trained extensively on his footwork and punch speed to the point where it appears that copies of himself are striking from all around an opponent. He also has high confidence in his enhanced speed as it is always shown that he usually prefers dodging enemy strikes than blocking. It is also shown that he's fast and alert enough to block an invisible strike from Sho Kano, one of the strongest members of YOMI. His standard jabs, according to Akisame Koetsuji, is of a normal top-class boxer.
- High Luck: It's shown that Takeda is a very lucky individual ever since he passed the impossible tests that James Shiba gave him as to get rid of him. The tests included trying to find an extremely rare twin-headed pachinko ball or catching rare fish fresh from the deep sea while doing impossible tasks. Another example was how he was able to counter against Lugh, a very intelligent fighter, after being outsmarted by him and eventually turn the tides and lay several blows unlike there first fight together.
- Sei Ki: Ikki uses Sei Ki, a style which allows him to fight with a calm and peaceful spirit instead of with rage and anger. During the fight Takeda was able to release his Sei ki on his own and completely overwhelmed Lugh. Despite having just learned how to use it, he was already skilled enough to perform Ki feints, which served as the basis for his Warp Punch. Ikki is the only person in the shinpaku alliance who has unlocked his Sei ki, and one of the only two people in the alliance who has been shown unlocking their Ki (the other being Miu Furinji).