In Gangnam: Daiso Gangnam Station Store 2 (109 Teheran-ro) and Gangnam Station

Store (422 Gangnam-daero), 10am–10pm. Real Barrier Moisturizing Glow Lotion (150ml) is ₩5,000 with 6,580 orders; 150ml is over 100ml, so pack it in checked luggage. The humidifier is small and light to pack. Both stores are near Gangnam Station, easy on your way back to the hotel.