i almost don't recognize yuyuko due the lack of her insignia and long hair..

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It's hard to recognize a character when you change her completely.

The thing is, she's not Yuyuko. Take a look at http://browse.deviantart.com/manga/#/d5901ud , it says that the pink haired girl is an OC and that the girl in the bunny suit is Rinnosuke's genderswap.

Now that makes a bit more of sense, although I still see too much of Sayaka in this Rinnosuke.