Yuunosuke Ogasawara enters Azusa Noyama's fifth-grade class as a transfer student, swiftly becoming the focal point of her romantic inclinations. His warm reception of her nickname "Azuki-chan" transforms her view of the moniker, prompting her to embrace it fully and kindle affection for him. His approachable nature endears him to classmates, though this widespread popularity stirs Azuki's jealousy, particularly during interactions with Yōko Sakakibara, who persistently meddles in their budding connection.

Born July 23 under a Leo sun, the eleven-year-old with blood type O balances video game enthusiasm and soccer agility with domestic talents—skilled in cooking and adept at babysitting, honed through caring for younger relatives. A pivotal moment unfolds when he shares a first kiss with Azuki after an injury from middle school bullies, sparking comedic misunderstandings rooted in childhood pregnancy myths.

His family background features a father who transitioned from amateur race car driving to international corporate work, ultimately relocating the family to New York City after elementary school. This move concludes his daily presence in Azuki's life, yet his narrative remains anchored by steadfast friendships with Ken Takayanagi and Makoto Sakaguchi, showcased through collaborative group activities highlighting his supportive nature.

Universally kind and responsibly mature, Yuunosuke treats peers equally, demonstrating childcare competence and readiness to assist others. His departure leaves an indelible mark on Azuki, symbolizing both the close of their shared childhood chapter and the ephemeral quality of youthful romantic bonds.