By the puffy like sleevess looks like Jintsuu's style.
Looking at their original official art, it seems like Naka has puffier-looking sleeves than Sendai, but not as puffy as Jintsuu's. Frankly they seem closer to Naka's here, and she seems a closer match to Cocoa personality-wise. But I don't know... the apparent difference could be unintentional (with the official anime post #1938329 it doesn't really seem the three are different as far as their sleeves are concerned).