The Monsters Are Here! Charge, Little Sister!

Though they live under the same roof, Zhe, who is already in college, and his younger sister Xiangxiang don't have much to talk about. That is, until one day he discovers that his model high school student sister has been secretly playing WOW, and is even the main tank of a guild! Then, during the carefree summer after his sister gets into a prestigious university, she patiently persuades Zhe to play WOW with her to improve their relationship...