Pico, a blonde-haired boy, works summer part-time jobs at his grandfather's beachside bar, Bebe. He is frequently depicted swimming nude or in a blue Speedo. His effeminate presentation occasionally causes him to be mistaken for a girl.

Early in his story, Pico meets Tamotsu, a Bebe regular also called Mokkun. Tamotsu approaches Pico believing him female, initiating a romantic and sexual relationship that persists after Tamotsu learns Pico is male. Tamotsu gifts Pico feminine clothing—including a ruby choker and panties—which Pico initially resists wearing but eventually adopts under Tamotsu's persuasion. When Tamotsu refuses to define their relationship or see Pico beyond a sexual object, Pico emotionally rebels by cutting his hair and running away. Tamotsu later finds him, leading to reconciliation.

Subsequently, Pico encounters Chico, a younger brunette boy swimming nude in a forest stream. Their close friendship evolves into a romantic and sexual relationship, with Pico typically in a submissive role though their dynamics show flexibility. After observing Chico's older sister masturbating, Pico introduces Chico to sexual experiences, becoming his guiding figure as their bond deepens.

Later, Pico and Chico meet CoCo, a feminine-looking boy with long black hair. CoCo forms romantic and sexual connections with both, temporarily straining Pico and Chico's relationship. Following friction, the three reconcile and engage in a threesome atop Tokyo Tower, where Pico generally assumes a passive role, though this varies.

Pico navigates these relationships centered on emotional vulnerability and a desire for connection, balancing bonds with Tamotsu, Chico, and CoCo while seeking mutual affection and understanding.