This was playing on the bus today. It's called Lovex4 and was used as the incidental music in the film The Chef, the Actor, the Scoundrel (厨子戏子痞子).
I would just like to say that this is what I get for ignoring the Cpop chart for so long. New jam. Maybe new favourite video too (though I suspect I don't need to see the film). Also, wiki tells me she's from Qiqihar, which is automatic bonus points imo //always wanted to go there.