Jun Yamamoto, a 16-year-old academically ranked third in his school, shares a close bond with his twin sister Megumi and childhood friend Ryuu Tsuji, whose protective nature solidifies their inseparable trio. Born to a music producer father and celebrated singer mother, Jun harbors a deep passion for music, though most accounts dismiss his skill—save for one source lauding him as an accomplished violinist.

A childhood encounter with a hypnotic television program intended to cure shyness around women fractured his psyche, spawning a split personality. Triggered initially by physical affection like kisses and later by interactions with his girlfriend Sakura Ushikubo, this alternate persona exudes an alluring charm that captivates women. A traumatic rejection during a childhood date, caused by this persona’s emergence, led Jun to shun romance until Sakura’s acceptance of both his identities allowed him to confront his fears, culminating in mutual confessions and a stabilizing relationship.

The alternate persona fades only when Jun loses consciousness, frequently induced by Megumi’s singing—a calming force for him despite its typically overpowering effect on others. Physically, Jun sports light brown hair and eyes, a slender frame, and a height between 167 and 172 cm. While his appearance remains unchanged between personas, his voice deepens and his demeanor grows assertively confident when the alternate self surfaces.

Jun’s relationships anchor his growth. His reliance on Megumi and Ryuu evolves as Sakura’s influence helps him embrace emotional independence, shifting from insecurity to self-assurance. Early interactions with Sakura saw him fleeing to suppress his transformation, but her persistence in embracing both sides of him fostered reconciliation between his fractured identities, reducing his dependence on Megumi and Ryuu for stability. This journey underscores his transition from fear-driven avoidance to confident self-acceptance.