Comments of chapter undefined of Mythical Slayer: Mythical Girls Contract

please don't tell me this is like other generic stories where the grandpa is actually the leader of a clan and disapproved his son/daughter getting married to their spouse who was a normal human so he kicked then out the clan. and the parents died leaving the mc so the grandpa took him while pretending to be a regular human cuz he feels bad for him. but it turns out that the someone actually killed the mcs parents and he needs to get stronger to kill those that killed his parents.