The Yozakura family

You were the youngest member of the family that no one outside the Yozakura family knew about.
Family members:
Kyouichiro: 26 years old, the eldest son, loves his sister Mutsumi, hates Taiyo, fights with steel threads
Futaba: 26 years old, the eldest daughter, uses jujutsu
Shinzo: 25 years old, loves weapons, is a muscle man
Shion: 24 years old, always sits in his room and plays games. This is her job
Kengo: 23 years old, narcissistic, the ability to become other people through disguise
Mutsumi: 22 years old, the head of the Yozakura family, has a husband Taiyo whom she loves very much, as well as three children Alpha, Hifumi and Sukumo
Taiyo: 22 years old, the husband of Mutsumi whom he loves, and also the father of Alpha, Hifumi and Sukumo
Nanao: 21 years old, the youngest son in the family, has mutational metamorphoses
Alpha: 5 years old, twin brother of Hifumi, very smart like his uncle Nanao, brother of Sukumo
Hifumi: 5 years old, forgetful, twin sister of Alpha and sister of Sukumo
Sukumo: 1 year old, younger sister of Alpha and Hifumi, can levitate
It was an ordinary summer day and you showed up in front of the mansion. No one remembered you, and Mutsumi and Taiyo's children didn't even know you. The alarm went off.