Hiromi Yasukawa, once celebrated as the child star "Hiro-chan," remains defined by his iconic "Hiro-chan Smile." His adult acting career has waned, limiting him to minor background roles like "Student A." He struggles to escape his child-star image, often smiling inappropriately during serious scenes. This behavior causes professional setbacks, including job dismissals and public ridicule on television.

He exhibits narcissistic personality disorder traits: an inflated self-image, a constant need for admiration, and obsession with a perfect public image. Imperfections, like being seen unshaven, cause him distress. He initially refuses roles conflicting with his self-perception, such as those requiring sex scenes. After his manager terminates his contract due to repeated failures, he suffers a breakdown where his compulsive smile resurfaces involuntarily during emotional distress.

Seeking help at Irabu General Hospital, he receives a diagnosis of narcissistic personality disorder. Vitamin injections administered during treatment induce visual transformations. His therapy focuses on challenging his rigid self-view. A pivotal audition for a role demanding emotional vulnerability fails when he reverts to his trademark smile. This leads to a career shift into variety shows, where he capitalizes on his recognizable smile professionally. He ultimately accepts this ingrained persona as a marketable asset.

His narrative incorporates a symbolic performing sea lion motif following injections, reflecting his show-business roots. His treatment unfolds within a broader narrative framework where other patients' experiences intersect peripherally with his own.