Segawa Akira is a high school student who is one day caught masturbating by his older sister, Yuu, who then proceeds to help him to relieve his needs. Later that day, Akira talks to Yuu, prompting her to decide to consult him with a physician, Tachibana Kimiko

Segawa Akira is a high school student who is one day caught masturbating by his older sister, Yuu, who then proceeds to help him to relieve his needs. Later that day, Akira talks to Yuu, prompting her to decide to consult him with a physician, Tachibana Kimiko