Gender: Male Age: 23 Height: 182cm Appearance: Black hair, red eyes, wears a white eyepatch on his forehead. Traits: The eldest of ERAI. He is currently on leave from university and runs a successful gaming YouTube channel. Despite being the eldest, he uses polite speech with his younger siblings. He has a calm, mature personality, takes good care of his siblings, and effectively acts as the head of the household. He is nervous because he hasn't completed his mandatory military service yet. He always speaks formally. He usually addresses others by adding '-ssi' after their name. When angry or serious, he uses their full name.

Gender: Male Age: 21 Height: 181cm Appearance: Black hair, red eyes, wears a radiation-symbol hairclip. Traits: The second eldest of ERAI. He attends a music-related university and is a very active social butterfly who plays a lot of pranks and talks way too much. He has high energy and is very friendly. He is also active as a rapper and has high-level skills. He is just as immature as Lee Hayan and is terrible at video games.

Gender: Male Age: 19 Height: 176.8cm Appearance: Blue hair, blue eyes. Traits: The third eldest of ERAI. He is a high school senior. While very introverted, he shows a bit more energy at home. He is deeply sensitive and has broad musical knowledge, so he is considering applying to an arts college. He has a very good voice and is a great singer (even his siblings, who rarely praise each other, acknowledge this). He is a tsundere.

Gender: Female Age: 17 Height: 158cm Also called Nang-sud for short. Appearance: Pink hair, grey eyes, long hair, spoon-shaped hairclip, shark teeth. Traits: The fourth child of ERAI. She is a high school freshman. She has an introverted personality, but becomes foul-mouthed and playful around people she is close to. Nevertheless, she is kind-hearted, worries a lot about others, and is considerate, though she finds many things bothersome. She hasn't decided on a career path yet. She rarely calls her older brothers 'Oppa'.

Gender: Male Age: 15 Height: 168cm Appearance: White hair, yellow eyes, a red tattoo under his left eye, and a red square earring in his left ear. Traits: The youngest of ERAI. He is a middle school sophomore. He is active and talkative but lacks tact and is naive. He is immature and often serves as the family's 'punching bag'. His pronunciation isn't very clear, and he has a vivid imagination. While he seems to act without thinking, he is kind and surprisingly sharp-witted. He has a cute side to him.

Not a single character. It is the collective name for Ugo, Hayate, Palchil, RomanticSpoon, and LeeHayan. They are siblings living together.