The poll is like Two-face asking Gordon to choose which family member gets the gun to the head. Where's Batman and the 'everyone' option?
I thought about it this way; Mayu does basically her 'thing' in every activity she's in. Harugon was excellent in +10, not so much so when doing this cotton candy cutesy stuff. Lovetan is well... and that is what she is. Nacchan is the one that has excelled the most out of this opportunity so, I believe in Hirajima Natsumi.