I think the little sister is saying "What are you guys doing?" but Google translator sucks most of the time... was really hard getting it to write the bottom Kanji on the right lol.
Yeah, that's pretty much what she's saying. Looks fun, in any case, and the characters looks pretty good, which is nice. I like Takemiya Jin, but her chara design can be a bit all over the place, sometimes.
Also, I think this is a doujin based on Love Live! Looks like Nozomi playing the pocky game with Eri and the "little sister" seems to be Nico barging in on them. :p
