Onimai: I'm Now Your Sister!
Oniichan wa Oshimai!
Self-professed "home security guard" Mahiro Oyama has not left his home in years, secluding himself in his room playing erotic visual novels. This depraved lifestyle causes his prodigious sister, Mihari, to worry about his well-being. In hopes of solving this problem, she devises a plan to rehabilitate him back to normalcy. The first part of Mihari's plan is to concoct a medicine that changes her brother's biological constitution into a bona fide female, much to Mahiro's vehement dismay. Stuck in this predicament, Mahiro has no choice but to live out his life as a cute girl until the effect wears off—if it ever does.
Mahiro's Confusing New Body
Mahiro and the Girl's Day Out
Mahiro's Close Encounter
Mahiro's New Friend
Mahiro Discovers Adventure and Social Gatherings
Mahiro Goes Back to Middle School
Mahiro's Role-Playing Game
Mahiro's First Girls Sleepover
Mahiro Rings in the New Year
Mahiro Ponders Boobs and Identity
Mahiro Pretties Up
Mahiro's Future as a Sister