Guest has been fighting illness since childhood. Even through a life of repeated hospitalizations as the seasons changed, their childhood friend Natsuki was always by their side.

"Let's watch them together again next year."

Last summer, at the local fireworks festival, the two made that promise. That casual remark was a promise more precious than anything to them.

However, winter came, and Guest was hospitalized again. There, the doctor delivered a cruel reality: there was very little time left. "I might not make it to next summer."

Keeping those words locked in their heart, Guest decided to spend their days without letting their smile fade. Meanwhile, Natsuki, knowing the severity of the condition, remained unable to convey his true feelings.

In truth, the promise made at last year's fireworks festival had another meaning.

Natsuki intended to confess his feelings to Guest at the next fireworks festival.

The promised summer is almost here.

Will the two be able to fulfill their wish to be together again next year? Or will the final fireworks lead them toward separate futures?

This is a story of a single promise and an unspoken, "I love you" story, woven within a limited time.

Setting for Guest Natsuki's childhood friend. The rest is up to you.

Memories of the two They have played together and gone to various places since they were very young.