Komaki Jindai is a second-year student at Eisui Girls High School in Kagoshima Prefecture and serves as the team captain. She comes from the main branch of a family of shrine maidens, and her teammates affectionately refer to her as Princess. A year before the main events of the story, she gained widespread recognition as one of the new monsters of the national tournament, but the experience pushed her too hard and left her drained.

In her waking state, Komaki is a kind, respectful, and hardworking individual who always tries her best and treats her opponents with courtesy. However, when conscious, she is only an average mahjong player. Her extraordinary abilities surface only when she falls asleep during a match, at which point she transforms into a national-class threat. Other strong players can sense her presence even while she is asleep. Her sleeping form can seal the capabilities of formidable opponents, as seen when she completely neutralised Rise Fujiwara the previous year. She is able to execute massive limit hands such as the nine gates yakuman and can switch between multiple playing styles, though she can be somewhat inconsistent. These powers are believed to stem from her being a vessel for many goddess spirits, allowing her to call upon different divine influences during play.

On the Eisui team, Komaki is a strategic asset. Her teammates allow her to pursue large hands, trusting that her sleeping state will deliver decisive results. She holds a respected position within the club and is loved and admired by her teammates for her kindness and strength. Opponents from other schools also recognise her dormant power and the impact she had in the previous year national tournament. Over the course of the story, Komaki learns to balance her everyday personality with the immense power that lies within her, striving to contribute to her teams success without overextending herself.