Bangkok has plenty of good Japanese restaurants, but many can be a bit chilly toward newcomers. Genji is the happy exception, and the staff is always pleasant. There's an excellent sushi bar and several small private rooms where you can enjoy succulent grilled eel or a Kobe beef roll with asparagus and fried bean curd. Set menus for lunch and dinner are well conceived, and are a nice change from typical Thai fare. Lunch seats fill up quickly, and dinner sometimes requires a wait.
Nai Lert Park Hotel Bangkok, 2 Wittayu (Wireless Rd.), Bangkok, 10330, Thailand