They announced that their new single would be coming in August when they revealed the two new baby members, but I'm honestly surprised they actually stuck to it.
I've been enjoying Up Up Girls (2)'s music more than Up Up Girls (KK) lately, and I can only imagine throwing Tsunku into the mix will keep it that way.
I'm going to enjoy that performance video. I want to see what level the tiny ones are working at for now.
Edit: I've watched the video twice now. The song sounds like a direct follow-up to "tte Iu Hatsukoi no Oyakusoku" from their third single. That was my least favorite song from that single (not that I loved the other one a ton either). The new members felt like an after thought in most of the performance. Hope falls on "Zenbu Seishun!".
That being said, I think I still like it more than the majority of songs from Up Up Girls (Kari)'s most recent album.