I'm My Own Girlfriend - Ch. 1 - From Man to Maiden?

[MangaDex]

 

[abdullah17]

Why does bro have full on girls clothes? He's literally... me?

 

[jetto_neko]

If you get isekai-ed to some unknown alternative earth, you should probably keep everything about yourself a secret at first. .
If it's your own sister, why not just tell the truth?