Hitotsu yane no shita

A car accident killed a couple, orphaning their six children. At that time, the eldest child, Tatsuya, was only 18 and had to attend marathon training. Lacking the confidence to take good care of his siblings, he separately relocated them to the homes of their relatives and adopters. However, after seven years and a career-ending injury, Tatsuya decides to reunite his brothers and sisters to live together under one roof. To his disappointment, he is met with resentment and discord.