A big running joke in Demon Slayer: why does Inosuke look like a girl? What’s the actual plot reason as to why?
Inosuke tends to look like a girl because he takes after his mother. The two look very similar, sharing the same attractive features.
Inosuke learns the majority of the information about his mother during the final arc. If you’re not completely caught up on the manga, I would tread lightly as to avoid spoilers of Inosuke’s backstory.
Inosuke’s Mother’s Backstory
Inosuke learns about his mother while facing off against Upper Moon Two, Doma. The demon claimed Inosuke looked familiar.
Doma reveals that his cult took in Inosuke and his mother to free her from an abusive husband. The mother was partially blind with a swollen face, but she was revealed to be beautiful after healing up.
“She had the same face as you, but she looked more soft and delicate. Your Mom, am I right? Oh, yeah! No mistake about that.”
Doma to Inosuke / Chapter #160
The demon planned on keeping Inosuke’s mother by his side, but she learned that Doma was eating the worshippers of his cult. She escaped and ran towards a cliffside, dropping Inosuke into a flowing river as Doma caught up and ended her.
Somehow, Inosuke ended up under the protection of a family of boars. His only memories of growing up, Inosuke liked to wear a boar mask in order to commemorate what he considers to be his true family. It wasn’t until he met with Doma in battle that he unlocked more memories of his true mother.
Where Else Does Inosuke Look Like A Girl?
Inosuke tending to look like a girl worked in his favor during the Entertainment District arc. Him, Tanjiro, and Zenitsu were tasked with dressing up as aspiring wives in order to scope out a demon. Inosuke’s looks helped him pass off as a woman in a more believable fashion compared to his two friends.