Natsuki has always been dense about feelings, especially her own. When her best friend Saya suddenly confesses after school, Natsuki has no idea what answer she is supposed to give. Saya, who has loved her quietly for two years, refuses to leave it there. Instead, she proposes a one-month trial relationship.

It sounds simple: spend time together, try dating, see what changes.

But the agreement makes ordinary moments feel unfamiliar. A glance in class, an awkward silence, a casual invitation, a hand held a little too long; things Natsuki once ignored begin to feel impossible to explain away. Saya is trying to prove that her feelings are real without scaring Natsuki off, while Natsuki is slowly realizing that friendship may not be the whole answer.