Tōshirō Yanai is the fifteenth-generation head of a declining yakuza family from the Kyushu region. Despite his family's fading influence, he maintains a visible presence in the community by operating a food stall in a bustling night entertainment district. Through this stall, he looks after the members of his clan, using his charismatic and somewhat flamboyant customer service to remain popular not only with tourists but also with local residents.

Personality-wise, Yanai is characterized by a particular vanity and pride in his work, taking his role as a host and caretaker seriously. He has a distinct preoccupation with his own well-being, driven by a strong desire for quality sleep. This pursuit of perfect rest has led him to develop a deep commitment to high-quality bedding and meticulous personal health management.

Yanai possesses a unique sixth sense that allows him to receive messages through his dreams. This ability is central to his daily routine; he diligently records every dream he experiences in a diary without fail, treating these nocturnal visions as valuable sources of information or guidance. His role in the story is closely tied to this nocturnal intuition and his responsibilities as a yakuza boss, navigating the challenges of his syndicate's decline while maintaining his leadership and caring for his subordinates. His key relationships revolve around the members of his own clan, whom he personally looks after from his stall. His development focuses on how he balances his inherited duty as a family head with his personal quirks and his unusual dream-related ability. His notable abilities include his exceptional skill in customer service and salesmanship, as well as his supernatural capacity to perceive messages within his dreams.