Bitter - Kare No Hisoyaka Na Seppun summary:

This story revolves around Hasunobe Yoshinari's (Sweet - Ano Amai Amai Aji) older brother. For Hasunobe Yoshitomo, co-heir and general manager of the first-class Royal Fort hotel chain, life is pretty sweet. The only bitter pill is dealing with the rival hotel chain that recently opened nearby. However, things start to look up when he escorts a beautiful drunken guest back to his room, but who is this mystery guy?