Mizuha's 17th birthday is ruined by a pandemic canceling events. Her childhood friend Mizuki unexpectedly declares his intent to date her, sparking a youth story about their friend group.

In a flooded world, a boy rescues a robotic girl from the sea. Grateful, she vows to be his "leg" until fulfilling her former master's order, leading to an unforgettable summer adventure.

Yoshida gets rejected by his crush at a dinner party, and while heading home he meets a homeless teenage girl.