Hairi Takahara
Voiced by: Shoya Chiba
During summer vacation, a boy came to Torishiro Island to sort through his late grandmother’s belongings. He had once been involved in swimming but distanced himself from it due to certain circumstances.

Shiroha Naruse
Voiced by: Kohara Konomi
A shy and introverted girl who has been isolated on the island. Her only close family member is her grandfather. She often gazes at the sea from secluded spots on the island.

Ao Sorakado
Voiced by: Takamori Natsumi
A friendly girl who easily befriends both men and women. She works part-time at a local snack shop and is beloved by people of all ages. Often seen sleeping in various places around the island, which has become a common sight for the locals.

Kamome Kushima
Voiced by: Hieda Nene
A mysterious girl encountered on the island, always carrying a large suitcase. She never reveals its contents. She seems to be searching for something, wandering the island with an old map, claiming it’s a treasure map.