If you were unimpressed with the nightlife in Tokyo, you'll be really unimpressed with Seoul.

The main gay nightlife area in Tokyo is Shinjuku Ni-chome, a few hundred meters east of Shinjuku Station. The Hyatt Regency Tokyo and Hilton Tokyo are about equally far on the west side of Shinjuku Station, and the Park Hyatt Tokyo is only slightly farther. The Keio Plaza is a bit closer. There's also the Shinjuku Washington Hotel if you're looking to spend less and don't mind a tiny room with a tiny window.

There are a few foreigner-friendly gay bars on Homo Hill, just off the main drag in Itaewon. Myself, I like Always Homme, a friendly, quiet little bar. The Grand Hyatt is up a hill not far away.