Product description ※Please note that product information is not in full comprehensive meaning because of the machine translation.
Kotarou Kirizaku, a third year high school student, had an older brother-in-law due to his father's remarriage.
That person was Shino Momota, whom Kotarou said two years ago, "Please give me the second button."
She was so happy to live under the same roof with her beloved Shino senpai, but at night she began to worry about Shino's suspicious behavior of going out without telling her parents. She got involved in an unexpected incident.
What happened to her first love that was so devoted to her? Kotarou