お兄ちゃんはおしまい!1

[DeepL Translation - needs review] Volume 1 Introduction: Mahiro Oyama, a reclusive young man, is turned into a girl by his sister Mihari, who drugged him with a mysterious drug. Toilets, bras...there's a lot about a girl's life that he doesn't know. What is her brother's destiny...?　The popular TS manga on the web has finally been published in book form!　The manga is also specially included in the book, and you can only read it here!

(Translator: DeepL)