ONIMAI: I'm Now Your Sister (Original Japanese Version)

One afternoon, Mahiro Oyama, an unemployed shut-in wakes up to realize he's turned into a girl.

When Mahiro gets a stomachache, Mihari realizes his pain may be related to the fact that almost a month has passed since he turned into a girl.

Mahiro meets Kaede, Mihari's old classmate from middle school. He quickly realizes how nice she is and becomes quite attached to her.

Mahiro loses to Mihari in a video game, so he has to do the grocery shopping this week as punishment.

Mahiro goes outside of his own volition to pick up anime merch from the corner store.

Momiji shows up at Mahiro's house with her two classmates, Asahi Ohka and Miyo Murosaki, to invite him out for parfaits.

Just when Mahiro is beginning to get used to middle school life again, finals are upon them. Despite his initial blasé attitude, Mahiro finds himself reluctantly handing in a 80% blank answer sheet after having slept through the entire first exam.

It's finally winter break and Mahiro is excited to get into his Winter Vacation Mode. Unbeknownst to him, however, Mihari invites Momiji and the others over for a sleepover. She hopes this will prevent a potential relapse into his old, shut-in ways.

It's Christmas and Mahiro is shocked to hear his own little sister has a date. Unable to shake his unease, he follows her through the festive hustle and bustle in secret, with Momiji as his escort in tow. Who could Mihari possibly be meeting with?

It's the start of the third semester and winter uniforms are now in effect. For Mahiro and the girls at school, this means braving the cold winter air in mandatory skirts. Who knows how Miyo will react when he and Momiji show up in matching scarves, too.

Horoscopes are all the rage at school right now, and Mahiro is curious to see what all the fuss about. According to his forecast, an important occasion is on the horizon and he may be in for a surprise or two. But what occasion could it be alluding to?

Mahiro and the girls take a trip to a Japanese inn over spring break. First they hit the town in their yukata, before heading to the open-air bath to detox. However, things go south when Mahiro begins to feel a familar tingling sensation between his legs.