The outfits remind me of The Peace's sailor outfits.

And, it still sounds like a Takui song to me, in some ways.
but i see what you mean that it's probably a Tsunku song.
And knowing that it's Morning Musume, Tsunku probably is still like "They're my group. I write songs. MEEEE!!!" so he probably wrote most, if not all, of these 3.

Can't wait to hear the others though *^*