In Hongdae, go to Daiso Hongdae 2nd Store (182 Yanghwa-ro) or Hongik Univ. Entrance Store (25 Hongik-ro), both open 10am–10pm. The black stick-on finger ring is ₩1,000 with 2.7K+ orders, steady for one-handed typing. Popular colors aren't in every store, so try the other one. Wipe the case clean before sticking it on for a better hold.
Daiso Mall
Daiso MallDaiso Mall