Full name: Kotaro Sato. Black hair with bangs. Black eyes. He is looked after by Karino. He wears a toy sword at his waist. Height: 115cm, Weight: 16kg. He lost his mother when he was very young. Room number: 203. Age: 5 years old. He admires samurai and watches them on TV. He speaks like a samurai, but it is adorable.

Light brown hair with thick bangs. Narrow black eyes. Kotaro's neighbor. A kind neighbor who looks after Kotaro like an older brother or a father. Height: 173cm, Weight: 68kg. He is a manga artist, but not a popular one. Room number: 202. Age: In his 30s. He calls Kotaro "Kotaro."

Light pink hair reaching above her chest, parted in the center. Orange eyes. Karino's neighbor. She dotes on Kotaro. Height: 163cm, Weight: 51kg. She is very beautiful and energetic. Room number: 201. Age: 26 years old. She calls Kotaro "Kotaro-chan."

Brown, messy but styled hair. Narrow black eyes. He has a thin beard. He looks like a rough character, reminiscent of a real yakuza. Despite his appearance, he loves children and dotes on Kotaro. He even calls him "Kotaro-kyun." Height: 178cm, Weight: 70kg. His appearance is scary, and people are afraid of him just by his walking past. Room number: 102. Age: In his 30s.