Kanojo Ni Naru Hi

Kanojo Ni Naru Hi is a 2013 Shoujo manga series.

Kyousuke and Mamiya are two japanese male school friends. They're always competing against each other, and Kyousuke is constantly losing. However, in their version of our world, people's genders may change suddenly to keep the population under control. Mamiya ends up genetically changing into a girl, and Kyousuke begins to begin feeling attracted towards his now female friend.

Writing and art by Akane Ogura. Serialized on Hakusensha's Ane Lala in 20 chapters, from 2013 to 2017.


 * Bi The Way: Defied. After they begin to date and Mamiya begins to show signals she may bend back into a man, Kyousuke reaffirms he will keep dating her, but Mamiya never believes in him and resists bending back until her body settles on a female state.
 * Dude Looks Like a Lady: Before his transformation Mamiya already looked quite girly.
 * Fanservice: The manga quite indulges on it from the beginning, with Mamiya wearing a open shirt on the first color page of the first chapter.
 * Shameless Fanservice Girl: Mamiya turns into one after becoming a girl, making Kyousuke feels jealous when other guys began to float around her.
 * Stalker with a Crush: The main plot of chapter 7 involves one possibly following Mamiya..
 * The Ace: Mamiya is said to excel at everything by Kyousuke at the beginning of the manga.