In Southern Japan, there lies the verdant Minamijuuji Island. One night, a youth by the name of Tsunashi Takuto arrives on one of the island's beaches. This youth, who had swam to the island from the mainland, subsequently enters Minamijuuji Academy's High School Division.

Possessing a positive and forward-looking attitude, he easily develops relationships with Agemaki Wako, Shindou Sugata, and various other people he meets at the Academy.

However, Minamijuuji Academy hides a big secret. Beneath it, 20 humanoid constructs lie dormant.

In this land that lies under a blue sky and surrounded by blue seas, a story of love, dreams and friendship begins.