Morisaki Yuuta moved into the city after his mother's death with his older sister; Ruri and attended the same highschool. In the school corridor, he bumped into a student in the name of Kusunose Hina who participates in the Tennis Club. From that moment onward, Yuuta remembered his childhood promise he made to the girl whom he used to play with when his mother was still alive. Set in an endless summer, the goal is to build a romance with one of the heroines. The game is similar to True Love Story 2 but features a "daily goal" system to guide your actions and track relationship progress through levels. Each heroine has two storylines, with one hidden character having just one.

Key gameplay changes include a "redo the day" option and a topic level system that affects conversations.