Dharmasagara is different from most Indian restaurants in town because it specializes in South Indian cooking. That is, you will not find the creamy and oily curries that are standard elsewhere, nor do they have naans. Instead, their fare tends to be lighter, coconut appears far more often, and the chefs are not afraid to properly spice the food (you can request your food to be spiced to Indian levels).
One of the dishes unique to Dharmasagara (I've never seen it elsewhere in Japan) is dosa (1600 yen for a masala dosa). It's a thin lentil pancake stuffed with potatoes and onions and served with coconut chutney and a lentil soup. The dosa measures about 50cm long and people sitting next to you are bound to ask the waiter what you ordered. The waiter tells us that restaurants in India make meter-long versions for families.
We ordered two set meals to continue: A larger set for non-vegetarians (3150 yen) and a smaller vegetarian set (2150 yen). The smaller set makes perfect sense and there's no need to order the larger one. It does come with a soup but that was the most disappointing part of the meal, and the meat is just one small curry among many. Plus, South India is where vegetarianism is more widespread so this is a good spot to give meat-free food a try, and also a good spot for vegetarians.
The curries were rather similar in both set meals-there were some spiced green beans, a lentil soup, raita (yogurt with cucumber and tomatoes), chutneys, chickpea curry and rice. Both came with a puri (deep fried and puffed Indian bread) that was absolutely delicious. To finish up, dessert was sweetened semolina (not that impressive), but some very good chai.
Right next door is a Tibetan art showroom. It was closed by dinnertime when we arrived but be sure to check it out if you get a chance. Dharmasagara is a good spot for South Indian cooking-you will find Indian customers sitting next to you and the food is spiced like you'd expect it to be. The menu can be a bit challenging if you're not familiar with Indian food, but the waiters speak fluent English and can guide you.