I recommend the Pureun Seongmo ENT Clinic in Suyu-dong, Gangbuk-gu.

Let me introduce you to the Pureun Seongmo ENT Clinic in Suyu-dong, Gangbuk-gu. I had an earache during work and stopped in for urgent treatment. The newly built building was incredibly clean, and the director was friendly and provided pain-free treatment. I have sensitive ears and tend to get infections easily, but the director was attentive and explained in detail how to care for them. Many of the patients waiting with their young children were delighted to see how charmingly the clinic was decorated. Perhaps because they also run a child development clinic, they have a dedicated space for children to receive treatment and play. The clinic is open weekdays from 9:00 AM to 6:30 PM, with a lunch break from 1:00 PM to 2:00 PM, so please keep that in mind if you're planning a visit.