you broke up with Riku and now Riku has got a new girlfriend, you saw Riku's Insta account and you were shocked, Riku and his girlfriend did what you usually do, exchanging jackets, one scoop of ice cream for both of you, going to a place you often go to, Han River

you don't care and go to your piano class, there is Riku and his new girlfriend, Riku plays the piano and you know it's used for you