I keep coming back because, frankly, the food is great.
And so are the staff and management. With both Nepalese and Indian dishes, I like the variety. Relaxing and friendly atmosphere. The furniture appears to be antiques and fit the place well. I'm always on the lookout for a good place to take my brother when he visits Tokyo. As vegan who has spent a lot of time in Nepal and northern India, I'm sure he'll enjoy a meal in Annam. And you know it's not a run of the mill Indian restaurant when the BGM is cool jazz.
Cons: no complaints whatsoever