Wan Sui, known as Banzai, is a wealthy student who transfers schools to escape attention tied to his family's fortune. He actively seeks an ordinary school experience by distancing himself from the privileges and scrutiny of his affluent background.

Within the new school, he forges strong bonds with Shi Fen and Zhen Kaixin, becoming one of their closest friends. His interactions with Shi Fen reflect typical teenage camaraderie and shared experiences.

Banzai harbors romantic feelings for Shi Fen's younger sister, Shi Miao. This interest subtly guides some of his actions and decisions within the group.

He has a younger brother, Wan Xing, who shares the same Japanese voice actor. Their sibling relationship and family background form part of Banzai's character context.