A high schooler with an unhealthy obsession with swimsuits. He lives alone with his father, and is heavily weighed down by his father's expectations. He joins the Girl's Water Polo team after being caught taking photos of swimsuits by his homeroom teacher.

Spoiler

It is revealed that his obsession is a result of his losing his mother at a young age. His mother was a professional swimmer, and when she died in a car accident, the only comfort and solace he could find was in the swimsuit that she left behind. Psychologically replacing his mother with swimsuits, Sugu developed a mother-swimsuit complex.