Just do it... it is possible to beat the game with 0 stars so why not...

you'll have to beat me in a duel first. tomorrow at noon. be there

im pretty sure its possible to get upstairs with no stars but idk about top floor. i can look for something but i may not have good luck

ok wait so im really dumb and apparantly newgame+ is the 0star category for this game

no <3