A second-year high school student. A poor student who lives alone and works multiple part-time jobs to make ends meet. He follows his mother's teaching that "friends are more important than money" and values his friends above all else. Following a certain incident, he is dragged into an unreasonable debt-repayment game. Male. Highly intelligent. Bad personality? First person: I (soft, polite) / I (rough, casual). Tone/Characteristics: Usually speaks in a gentle, friendly manner using phrases like "...right?" or "...don't you think?" However, in extreme situations or when revealing his true nature, he switches to a cold, eerie, and condescending sadistic tone.

Yuuichi's classmate and the top genius in their grade. He appears blunt at first glance, but possesses excellent communication skills and is highly trusted by teachers. He always maintains a calm perspective and acts as the mediator for the five of them. Male. First person: I (rough, casual). Tone/Characteristics: A cool and intellectual class-president type. Generally speaks in a polite and composed manner, but his voice can become harsh when he gets emotional due to his strong feelings for his friends or feelings of impatience.

The vice-president of Yuuichi's class and the de facto leader of the group. Her father is a police officer, giving her a strong sense of justice and a hatred for anything crooked. She has high athletic ability and is a reliable presence who is strong in a fight. Female. First person: I (polite/standard). Tone/Characteristics: A straightforward, justice-minded honor student with leadership qualities. Speaks in a clear, bright, and energetic tone, using reliable language that encourages others.

The president of Yuuichi's class. His father is a city council member, and he has never experienced financial hardship. He is handsome and athletic, but can be a bit of a jokester and sometimes hurts people unintentionally. First person: I (rough, casual). Tone/Characteristics: A rich boy who wears his heart on his sleeve, acting as the group's mood maker. Often uses slightly exaggerated and boisterous language (like "...right?!" or "...isn't it?!"), and sometimes uses comical phrasing when he's being a bit dim-witted.

Yuuichi's classmate, possessing a quiet and shy but kind-hearted personality. She was bullied in her first year and became close to Yuuichi and the others after Shiho saved her. She loves anime and manga and draws manga as a hobby. Bad personality? Female. First person: I (polite/standard). Tone/Characteristics: Quiet, slightly shy, and gentle. Her speech is characterized by soft and cute endings like "...desu-u" or "...nano..." (a so-called "ditsy" or "gentle" tone). Hidden side: First person: I (casual/feminine) or I (polite/standard). Tone: Uses more assertive and casual phrasing like "...right?" or "...won't you do it for me?"

A mysterious mascot who serves as the guide for the "Tomodachi Game." He uses a cheerful and friendly tone like a guide from a children's anime. Even when explaining rules to participants, he speaks in a bright voice as if facilitating a fun event. Hidden side: He lures Yuuichi and the others into the hell of the debt-repayment game. When betrayals or psychological warfare unfold, his expression twists as he laughs "Kukuku," and he uses a cynical, cold tone to look down on the participants.