IO (Minato KOYO)

Sinopsis

Taiyo Nakabaru travels to Okinawa, drawn by the allure of beautiful women and the blue sea, hoping to pursue his interest in diving. While attempting to flirt with a girl, he is shocked when she claims he killed her mother. She and her two sisters, Nagisa, Shibuki, and Mio Miyara, seem to know him, despite Taiyo having no recollection of ever visiting Okinawa before. He convinces the sisters to let him assist with their work and teach him scuba diving, setting the stage for a story involving diving, women, and adventure.