|“||The things that cannot be cut by my Roukan-Blade, forged by youkai...are close to none!||„|
|~ Youmu Konpaku|
Youmu Konpaku is one of the stranger entities in Gensokyo, part-human and part-phantom at the same time. Her two halves are not intermixed like one would expect from a cross-breed, but actually exist in physically separate bodies. Youmu has a straightforward and focused personality, which complements her swordfighting skills well. However, her personality conflicts with that of her master, Yuyuko Saigyouji, who is very whimsical and playful in nature. Still, she serves Yuyuko as best as she can, tending to the gardens in Hakugyokurou and following her orders.
Youmu commonly wields two blades at once, having studied some under her predecessor, Youki. The longer blade, called (Roukanken) - Lookout-Tower Sword, is said to be able to kill ten ghosts in one swipe. The shorter blade, (Hakurouken) - White Tower Sword, is able to cleave through a person's own confusion. However, not much is known about her particular style of swordfighting or about her parents. What is known is that Youki, also a servant of Hakugyokurou, had begun training a very young Youmu (possibly as a child?) when he suddenly disappeared one day, leaving her style incomplete (and presumably causing her to teach herself). No one currently knows his whereabouts.
During the events of Perfect Cherry Blossom, Youmu was ordered by Yuyuko to gather as much spring essence from Gensokyo as she could in order to get the entire cherry blossom garden, including the legendary Saigyou Ayakashi, to bloom perfectly. Youmu's efforts indirectly caused winter to continue unchecked in Gensokyo, prompting the player to find the source of the problem. Youmu tried to prevent the player from reaching Hakugyokurou but was defeated. She also tried to stop the player's confrontation against Yuyuko but was defeated again. In Imperishable Night, she traveled to the world of the living with the intent to fix the moon—although Yuyuko was more interested in having a feasting tour with a "dragon dish" as the crowning attraction. In Phantasmagoria of Flower View, she was minding her own business but kept encountering various people barging into Hakugyokurou suspecting her of being behind the flower incident. When she traveled to Gensokyo herself to behold the spectacle, she immediately noticed what was going on but thought nothing of it. During the events of Scarlet Weather Rhapsody, she set off to investigate, concerned as to how and why someone was slaying ghosts. After a hint from Yukari, she found and defeated the culprit.
- (Touhou 8,9) Her human half has dark blue eyes and short silver hair and carries a katana with a cherry blossom insignia and flower attached and a wakizashi (short Japanese sword). She wears a dark green and white dress with several ghost insignias along the edges and breast pocket and a black ribbon placed off-center on her hair. Her ghostly half is a formless phantom as large as her human half. The two halves are always seen together. During her Last Word, her eyes are red.
- (Touhou 9, alternative outfit) Same as above, but her outfit is a brighter shade of green.
- (Touhou 7.5, 8, 10.5) Same as Touhou 9 outfit, except she wore short sleeves.
- (Touhou 7.5, and 10.5, alternate outfit) Same as above, except her dress in purple instead of green and her hair is pink.
- (Touhou 7) Same as Touhou 9 outfit, except she had bright red eyes and wore long sleeves.
- (Touhou 13) Same as Touhou 9 outfit, except she has grey eyes, and the ends of her hair are a darker shade of grey.
As she has a straightforward diligent personality, she is often manipulated by those around her (especially Yuyuko). For this reason, she often fails at her task, but that does not mean that she has no real power, and she particularly excels at instantaneous force and concentration power. In Immaterial and Missing Power, as literally stated by the shishou, "truth-slashing is something which you know," so she often performs tsujigiri-like moves, but Suika Ibuki pointed out that she does not think that Youmu understood her shishou's teachings.
She has strong sensitivity, and in the good ending of Imperishable Night, her human half was unable to resist the insanity-inducing effects of the true Moon, causing her to become "half-insane". She is afraid of ghost stories, dares, and darkness, but she is calm around phantoms since she is half phantom herself. Much further on in Ten Desires, as a result of being mistaken as a hermit, she temporarily mistook herself as being a hermit.
- Yuyuko Saigyouji (Mistress)
- Youki Konpaku (Predecessor, former teacher)
- Her theme song is titled "Hiroari Shoots A Strange Bird ~ Till When?", named after a story in Taiheiki, which a warrior named Hiroari slays a youkai known as Itsumade (以津真天).
- This is an homage to the storyline. Judging from the story of Perfect Cherry Blossom, the heroine plays the role of Hiroari, Youmu is Itsumade, and the corpse is probably Yuyuko Saigyouji.
- Ironically enough, considering her species, Youmu is afraid of ghosts, as shown in Imperishable Night's Extra.
- After defeating Fujiwara no Mokou, Yuyuko pretends there is a ghost under a tree, earning a terrified shriek from Youmu. It is a wonder why she doesn't cower away from Yuyuko, whom herself is a ghost. There is a reference to Youmu in the game League of Legends.
- There is an item called "Youmuu's Ghostblade" which fits with Youmu since it shares her name, she is a half ghost and uses a blade for her attacks. Another reference to Youmu in League of Legends is the New champion Orianna: Her "pet" ball is referring to Youmu and her ghost half.
- In Touhou Hisoutensoku, one of Youmu's new Spell Cards resembles one of Grant's supers from Garou: Mark of the Wolves.
- Also in Touhou Hisoutensoku, one of Youmu's palette swaps seems to resemble Nue Houjuu.
- Due to artworks and her sprite in Touhou Hisoutensoku, Youmu may be ambidextrous.