Today I was taken to an old curry restaurant called Yamagoya (山小屋), down a small side alley off the main road in Nagano city centre. It was excellent. Their lunchtime set menu consists of three choices of curry with rice, and all come with soup, salad, and afterwards ice cream and coffee.
I chose the most expensive curry with bacon, potato and chicken katsu, for ¥895 (£7). I thought it was really superb, not really like the "normal" Japanese curry, but with more of a rich taste closer to a non-spicy curry you might get in the UK. If anything I'd have liked it a little more spicy, which you're able to order for ¥105. Next time I might pay an extra ¥105 for the larger portion (中盛り), although they also do a much larger (大盛り) portion for ¥210. All in all, a great find for my curry needs!