All in all, good premise. Basically Holy Grail of Eris but going towards a smaller scale of plot (as in not a national threat level) of the grandma mystery and SoL of their detective life? Hell yeah.
The family was really confused
Dad "YOU ARE BANISHED!"
FL "Okay, I accept"
Dad "UUUUH! WHAT?"
Dad "ANYWAYS, YOU ARE BANISHED!"
FL "Sure"
The ML also has bad vibes, tbh.
Kinda think that this work really should've been through an editor or something. Either that, or the translation is botched to the point of a rewrite