![large.jpg](https://media.kitsu.io/anime/poster_images/11323/large.jpg)
Masaomi is Mari's 25-year-old brother who quit school early to work, already moved out and married at the age of 22. Their parents work all the time. Mattsun told him that he's in love with Mari and he said that he approved of it as long as Mattsun's serious.