I like "It's Up To You", even if it sounds like an American top 40 song from summer 2016. "HAPPY NAKED!!" would be a good workout song. It actually started growing on me more while I was listening to it! "BIG BANG" is an exciting name for a pretty dull song.
I feel like "HAPPY NAKED!!" is almost there, but something is missing that's keeping me from really enjoying it. What that something is I'm not sure I can actually pinpoint.
Seriously though, Honoka’s a ridiculously adorable kid but my actual fave, at least in the doki-doki area, is Maachan. She looks in that Santa outfit with those earrings.
Also, Yuria kind of reminds me of Shimamura Uta with that little bit of spoken dialog.
And the arpeggio-like sound of the“Sekai de ichiba~n kawaii” line makes me think of Gag 100kaibun.