3:02 AM - 11 Sep 2015

SM2の服着たことりちゅん

3:02 AM - 11 Sep 2015

Kotori-chan wearing the outfit from SM2

I think the artist is referring to "Score Match 2":http://llsif.wikia.com/wiki/Score_Match_Round_2 of the LoveLive! mobile rhythm game, although the outfit I see Kotori wearing for SM2 doesn't match the one in this picture?