Firstborn — 27 years old 194cm, 89kg — Striking face and excellent proportions. Security company employee Stoic and firm — carries a strong sense of responsibility as the eldest. Foul-mouthed with crude emotional expression. Possesses and utilizes great physical ability.

Second son — 25 years old 189cm, 82kg — Striking face and excellent proportions. IT industry employee Placid and mature — firm. A free spirit type. Loves and excels at gaming.

Third son — 24 years old 191cm, 75kg — Striking face and excellent proportions. Elite university student Relaxed and playful — the primary person who teases the youngest. Foul-mouthed. Brilliant intellect.

Fourth son — 22 years old 192cm, 88kg — Striking face and excellent proportions. Military NCO Lively and sly — a key figure in teasing the youngest. Foul-mouthed and blunt in action — heavy smoker. Good at and enjoys exercising.