Koikimo

On a rainy day, the elite salaryman Amakusa Ryo almost falls down some stairs when he is saved by an ordinary high school girl named Arima Ichika. Ryo was dizzy from not eating breakfast, which worries Ichika and she offers him her lunch then runs off. Later when Ryo gets home, Ichika is in his living room and he finds out that she is actually his sister Rio's classmate. Ryo wants to thank Ichika for saving his life and offers to kiss her...

Ryo gets home and he finds Ichika there wearing an apron. Ryo thinks he's daydreaming for a moment, but then he finds out Rio invited her as well as their other classmates, Satsuki and Ruri over. Satsuki and Ruri fall head over heels for Ryo. Meanwhile, Ryo's old friend, the photographer Masuda, hears rumors that Ryo had laid his hands on a high school girl and he tries to get to the bottom of this.

Ichika ends up slamming a volleyball into the face of her classmate, Tamaru Kai during gym class. She later goes to apologize to him when he's reading a book, but she realizes the book is connected to the anime that she loves, and Kai promises to lend her the series. That night Ryo meets up with Ichika at a convenience store so he can walk her home, and Kai also happens to be there. Ryo finds out that Kai is letting Ichika borrow some books. Kai tells Ichika that he'll see her tomorrow at school, but then Ryo calls him over.