I had a lot of meals at Taj Mahal, when I lived in Hokkaido! I used to travel to Sapporo by train (about 45 minutes) just to meet some friends for the best Indian, probably in the whole country. The heat factor/spice level seemed very authentic... Although I'm not Indian. Anyway, if you're tired of ramen and sashimi, you ought to consider Taj Mahal as an option.
I have came to sapporo factory to try this halal food indian restaurant. it offers indian dishes such as rices, curries and tandoori. Their service is great and their food is delicious so if you are looking for indian food in sapporo, you can try their restaurant.