Yomi is a middle school student who spends his days playing video games with his friend Light. Younger than Light, he sports a permanent sleepy expression and communicates in clipped phrases, using fewer words than his peers. His personality shies away from trouble, showing clear reluctance when faced with demanding situations.

He harbors a notable fondness for macaroons. Transported to a fantasy world on a mission to rescue Princess Melody from a demon lord, Yomi views the quest as a chore rather than an adventure. He wields a slim staff tipped with an orb as his weapon.

Throughout the journey, he frequently derails progress by engaging in off-topic conversations with Light and Alpha. While Princess Melody remains imprisoned, Yomi occasionally idly wonders about her appearance.