暗殺者ABC

They say they have known Leen since he was a baby. They are Leen's bodyguards, but prefer to call themselves his assassins.They are Leen's swordsmanship teachers and are relentless in their teaching. They always beat Leen to a pulp, but say that it's tough love.They say that their real names are "Ahonasu" Bakanasu", and "charanasu", Leen does not know their actual names but understands that they have their reasons to hide it.For some reason, they are very strong against demons.[From official site]