Tasuku Nakamura, who was thrown into the sea in a marine accident and tried to help his best friend, instead ended his short life of 25 years.

Formerly a mediocre office worker, when he opened his eyes, he was in the form of a six-year-old baron's daughter, Sophie Linier.
At first she was confused by the changes, but she was reincarnated as a beautiful girl and decided to live as a lady in a different world.

The struggle of a 6-year-old girl with the soul of a 25-year-old male begins ... !!