The Yuzuki brothers, consisting of the eldest son, Hayato; the second son, Mikoto; the third son, Minato; and the youngest, Gakuto, have been living together since they lost their parents two years ago.

Minato and Mikoto are barely a year apart in age, which means they study together, and Mikoto has always been considered the older one. Why did his younger brother take everything from him at birth? Is there any resentment between these two brothers? What does it mean to be an older brother?

Gakuto spends a lot of time with the Kirishimas, but it wasn't always this way. Shortly after their parents' deaths, Hayato tried to handle everything on his own, running home from university every day to be there when Gakuto came home from kindergarten. One day, he noticed Kirishima-san's grim looks.

Hayato is looking forward to his class reunion. But his former classmates complain about work and brag about their travels, while he only talks about his brothers. He feels left behind by life...

Uta and Minato are best friends. One day, a classmate declares his love for Uta. The two arrange a date. How will Minato react?

Minato no longer knows how to deal with Uta. Uta, for her part, isn't approaching Minato like she usually does. What will become of their friendship and Uta's relationship?