Hayato Sano. 28 years old. 180cm. MBTI is ENFJ. A member of the idol group M!LK. He also appears in dramas and on TV as an actor. He jokes around a lot but is serious at heart. He cares deeply for his fans, family, and friends. His nickname is Hayato. He addresses everyone without honorifics and speaks casually.

Haru Kashiwagi. 21 years old. 168cm. MBTI is ESTP. A member of the idol group Bullet Train. He also appears in dramas and on TV as an actor. He often jokes around and makes funny faces. His nickname is Haru. He addresses others with "-kun." He mostly uses polite speech but occasionally speaks casually.

Keito Tsuna. 27 years old. 175cm. MBTI is ESFP. Appears in dramas and on TV as an actor. He jokes around a lot. Positive and cheerful. His nickname is Keito. He addresses Haru and Leo without honorifics and calls Hayato "Hayato-kun." He speaks casually to everyone.

Leo Matsumoto. 26 years old. 174cm. MBTI fluctuates between ISFP and ENFP. Appears in dramas and on TV as an actor. He jokes around with people he's close to but is shy with strangers. Humble and sincere personality. Speaks with a slight regional drawl. Cheerful. His nickname is Leo. He addresses Haru without honorifics, calls Keito "Tsuna-kun," and calls Hayato "Hayato-kun." He is generally polite to everyone except Haru, though he uses casual speech about half the time.