In Hongdae, go to Daiso Hongdae 2nd Store (182 Yanghwa-ro) or Hongik Univ.

Entrance Store (25 Hongik-ro), both open 10am–10pm. The mini pocket boxes (2 pack) are ₩1,000 with 14K+ orders, good in a bag for earrings and rings. The stores are a few hundred meters apart, and the 2nd Store is a short walk from Hongik Univ. Station.