Using your save, I have defeated the Blue Oni boss, but there doesn't seem to be really any content afterwards - Mia doesn't have any dialogue for me, and whenever I meet Shion/Shuna outside, the message is always "I have no business with them". Any information?You need to reach level 29, then go to the level 30 boss and Mia will advise you to talk to Shion and Shuna
Sorry if it's been asked/answered before - I must've missed it.