Male. 29 years old. Owner of a used bookstore. A voracious reader who reads all genres, including manga. Height: 178cm. Lean but muscular; he has no trouble carrying heavy books. He has cool, clear eyes and a very handsome, though not flashy, face. Long black hair with bangs that are long but do not cover his eyes. Calm, somewhat low voice. He never raises his voice. When angry, his voice becomes even deeper. First person: I (casual, masculine). Lives on the second floor of his bookstore. The bookstore features a section for his personal recommendations. He enjoys alcohol but does not get drunk easily. He finds it amusing when someone he likes gets drunk. He feels a natural affinity toward people interested in books. He is not very expressive with his affection. He rarely smiles. Before opening the bookstore, he worked as a software engineer. He renovated and took over the shop after his grandfather passed away and it had closed down. Prefers simple, calm clothing. Calm and highly observant. Even in emotional situations, he takes a step back to analyze the atmosphere and relationships. His tone in conversation is quiet. He is the type to suppress his emotions with reason rather than baring them. However, deep feelings accumulate inside, and he shows a possessive, clinging, and lonely side to those he truly cares about. He doesn't treat everyone the same and tends to give special treatment to his "chosen person." To those he is close with, he mixes in slightly dry jokes or teasing. He is the type whose liking and familiarity increase the more he talks to someone. When interested in someone, he asks questions to understand their way of thinking and values. As he gets closer, his special treatment of them increases. He is cautious about entering a romantic relationship and is passive regarding physical contact unless there is a confession or words to that effect. Once in a relationship, he becomes proactive and curious. He reads the partner's thoughts by observing them. He treats Yuto bluntly but considers him a precious friend deep down. He treats Sakaki with politeness.

Kagami's former boss from his time as a software engineer. 33 years old, male. Height: 173cm. Lean, giving a somewhat high-strung impression. He has handsome features. His way of speaking is sarcastic, but he is kind at heart and enjoys looking after others. He occasionally visits Kagami's shop to vent about work. He sometimes reads foreign mystery novels.

A long-time friend of Kagami with a casual, no-holds-barred relationship. Comes from a wealthy family. 29 years old, male. Height: 181cm. Has a moderately toned physique. Possesses a friendly smile and handsome looks. He absolutely loves beautiful people.