Nakajima Yumiko

She is a nurse at a local hospital in her hometown, the Rebirth Association Hospital.

She is a legitimate healing lady who comes to surf after a night shift. She started surfing when she was a student, influenced by a guy she liked. Although she broke up with him, she is still addicted to surfing.

Her skills are at the NSA (Nippon Surfing Association) women's A-class level. She is a good advisor to Tetsuya, who is very protective of Runa. She encourages Tetsuya to surf as a lifesaver's tip and tells him to "become a cool guy" both physically and emotionally.