Saika and Kenichi were inseparable as children. She stayed in their hometown while he moved to Tokyo for work, and they have not met since their coming-of-age ceremony. Their reunion revives more than nostalgia: as teenagers, each had quietly begun seeing the other romantically, but neither dared confess for fear of ruining their friendship. They grew up and drifted apart with years of love left unspoken. Now, spending time together again beneath the fireworks, the two adults finally face the feelings they have shared all along and discover where their mutual secret love will lead.