You and Yui spend your first summer together. Yui playfully frolics on the beach and you two become even closer.

You and Yui become closer, but something seems off. Yui does something rash after she realizes something feels off between you two, which leads to your first fight.

Yui starts sulking and acts rather jealous all the time, but you tell her how you really feel. Despite the supposed strains in your relationship, in the end, this should all make your bond even stronger.

You live and work at a bathhouse that’s in danger of going under and get worked to the bone by the owner's granddaughter, Minori. You’re both very close friends, almost like brother and sister, and another fun-filled day is about to begin.

You and Minori go to a local summer festival. Somehow, Minori frolicking in her yukata makes her seem a little different than usual. That night, you both enjoy the fireworks and then have a serious conversation.

Minori decides what she wants to do in the future, but she realizes how difficult that will end up being. She doesn’t want to change, but she realizes she has to. The solution that Minori comes up with ends up shocking you...

You somehow agree to go along with Minori’s experiment of how it would feel if you two were married. She then tells you why she wants to protect the bathhouse, which ends up making the bond between you two stronger.

You end up running into a college student named Amatsuki Mashiro, who lives in the same apartment building as you. Your first encounter doesn’t go very well and she ends up calling you “Mr. Pervert,” but this leads into a more meaningful relationship.

Mashiro spent most of her life concentrating on gymnastics and is now troubled because she feels like she can’t do anything else. You then help her with practicing for interviews, cook with her, and other things, making you closer. You also feel troubled about work and you two start talking a lot more.

Mashiro still struggles to find a job, but then you end up finding the perfect job for her.

Mashiro thanks you for helping her move forward, which brings you happiness as well. The girl who loves gymnastics and her “Onii-san”... Where will your story go next?