The first Kanji appears to be [生] so it's a guess that the second is [徒] but that is only a guess. Putting them together is and it's read [seito] meaning student.
The third kanji is [会] which I'm going to have to play the guessing game again with based on the pairing list I've found I'd say that the last kanji that is mostly cut off is [同] putting them together and their read [kaidou] meaning to coordinate jointly or a club.
生徒 Seito = Student 会同 Kaidou = Club/Council
So the tag in Rin's hand says "Student Council"
And no I do not know Japanese. I just have a Kanji dictionary and Wikipedia to help.
Sorry but I couldn’t get the note to hover over the tag in Rin’s hand. First time trying to use the thing.
