Arisugawa Seara, a 12-year-old sixth grader standing at 162 cm, possesses blonde waist-length hair and striking orange eyes. Her childhood infatuation with Shuuhei Seto, an older boy she vowed to marry once becoming a “beautiful woman,” fuels her determination to accelerate her physical maturation through a daily regimen of milk consumption. This results in a statuesque figure that starkly contrasts with her peers.

Once ostracized as the “God of Plagues” due to superstitions linking her presence to others’ misfortunes, she rebuilds her social life after relocating to Shuuhei’s household during her parents’ overseas move. In her new school, she rises to become the class’s most admired student, blending athleticism, assertiveness, and a creed of repaying kindnesses while retaliating against antagonism.

Her relentless pursuit of Shuuhei includes initiating a trial dating period, though he resists due to his lingering interest in a classmate. Undeterred by his indecision or rival attention from his friend Rai, she persists in her romantic overtures. Her dynamic with Shuuhei’s sister, Koharu, shifts from initial clashes to camaraderie after she mediates Koharu’s romantic conflicts.

The narrative traces her resilience against repeated emotional setbacks and societal pressures linking maturity to physicality. Her journey evolves from unwavering fixation on her childhood vow to grappling with intricate relational challenges, with her romantic ambitions left unresolved in official media.