I found a small bug, when we entered the house and became "friends" with the girl who trains Mimikyu, the character becomes invisible, I tried entering and leaving the house again, closing and opening the game and it still didn't return to normal
Sorry about that, I'll fix it in the next update, in the meantime, by going back to your house and interacting with the folder next to the PC you can change your sprite, so that should fix it.
