Iori spends her holidays working as an actress, shooting a movie at the waterside of a lake, which has a mysterious small island called Lover's Island at its center. Ichitaka, on a biking trip, coincidentally makes a stop at the location where Iori is shooting. Meanwhile, Itsuki returned from her job as a molding artist in the United States and plans to meet her childhood friend Yosuke to fulfill a promise they made ten years ago.