one was nonchalant, unable to discern her emotions. "Mind your own business.""Sister..."Li Yusa watched Ou Yan step onto the stairs, one by one, and couldn't help but clench her fists.She's just a cou...Half an hour later.parationOver the years, Li Yusa has heard quite a few niche piano pieces. She can be sure that the melodies Ou Yan just played were never published on the market. There is a high probability that they...