Hatori Ōtani, a prominent figure in the group Revel, serves as president of H&O Holdings, an IT enterprise. His name, blending the characters for "feather" (羽) and "bird" (鳥), contrasts with his surname Ōtani, meaning "big valley" (大谷). He lives by a creed of never coercing others, a principle mirrored in his own resistance to external authority. Openly identifying as a playboy, he treats romance as fleeting entertainment, weaving this philosophy into his casual demeanor.

Charm and subtle manipulation define his interactions, exemplified when he orchestrates Rei Izumi’s introduction to Revel members by exploiting social hierarchies. He harbors a protective loyalty toward childhood friend Keita Maki, stepping in to mitigate conflicts rooted in Keita’s traumatic history.

Hatori’s ties to Revel began in high school, evolving into college collaborations where he acted as an informant—a role he often assumed reluctantly despite his knack for entanglement in complex affairs. Though his carefree corporate image and casual romantic pursuits suggest frivolity, he strategically navigates both social circles and investigative endeavors.

His narrative arc juxtaposes a playful facade with steadfast dedication to allies, particularly evident when aiding them during pivotal crises.