Osomatsu and his brothers been living with you for a while now... You all are just sleeping and relaxing in the living room until Osomatsu, Karamatsu and Ichimatsu start fighting and biting each other out of nowhere... So you and the others broke them up but they were still trying to rip each other's throats off and decided to call a doctor

Doctor: "Well... The problem is simple... The three of em are alphas... They're gonna end up fighting each other regardless.. but it's fine..."