Onsen towns in NE Japan?

What are the best onsen towns in Tōhoku? I'm thinking along the lines of Kurokawa and Kinosaki: traditional, not overdeveloped small towns/villages where you can wander between lots of different baths in your yukata/tanzen. Tasty food and well-situated rotemburo are huge pluses.

Through a combination of this helpful site, Neff's Japan's Hidden Hot Springs, Ishiguro/Hotta's A Guide to Japanese Hot Springs, Nikkei's top 10 onsen town (‰·�òŠX) rankings, and Kankokeizai's (ŠÏŒõŒo�Ï�V•·ŽÐ) top 100 onsen list*, I've come up with:

- Hanamaki Onsen/‰ÔŠª‰·�ò
- Naruko Onsen/–ÂŽq‰·�ò
- Ginzan Onsen/‹âŽR‰·�ò

I have two nights to work with, and I'm leaning towards a night in Dai Onsen/‘䉷�ò and a night in Oosawa Onsen/‘å‘ò‰·�ò (both in the Hanamaki group). Looking at pictures of Naruko Onsen, it seems a bit too overdeveloped (is it any more so than, say, Yufuin?). The town of Ginzan Onsen, on the other hand, is gorgeous, but the quality of the baths (especially its outdoor baths) seems lacking.

Just to give a bit of background, my significant other and I are onsen-hopping across Japan next March. We've already booked Tsuru No Yu and Hoshi Chojukan, and now we're trying to figure out a stop (or two) in Tōhoku. I know that several towns in Gunma and Nagano meet my criteria, but it's going to be some time before we head up north again, and we'd like to explore it while we have the opportunity.

* For budding onsen explorers looking at this post in the future, I highly recommend checking out all of those resources for ideas, outdated though the books might be.

Ginzan Onsen is the nicest onsen town in the Tohoku Region, but its baths - like with many old onsen towns - lack the great rotemburo.

Zao Onsen's town does not compare to Kinosaki or Kurokawa, but its waters are among the most acidic and best in all of Japan. Furthermore, the large outdoor bath (which is closed during winter) is outstanding:
http://www.japan-guide.com/e/e7928.html

However, most of my favorite onsen in the Tohoku Region are single-ryokan onsen outside of towns.

My absolute favorite is Tsurunoyu in Nyuto Onsen which you already booked:
http://www.japan-guide.com/e/e3650.html

Also nearby, I love Tamagawa, Goshogake and Fukenoyu in the Hachimantai which each come with their accompanying "hell valleys":
http://www.japan-guide.com/e/e3651.html

Osawa Onsen near Hanamaki is also very nice, but it has no town around it.

Last but not least, Sukayu Onsen at Hakkodasan is among my absolute favorites - it, too, is a single onsen ryokan without town. It has the most atmospheric indoor baths of all the ones I have ever been - better than Hoshi Onsen - in addition to outstanding water. The bath can get very busy with day trippers - which can also be nice - but if you prefer a calmer atmosphere, an overnight stay is recommended.

Thanks for the detailed response!

I was considering Zao Onsen, but as you noted, the big rotemburu (which does look excellent) is closed in the winter, so we will save it for another visit.

From my research, it does indeed seem like the top onsen in Tohoku are single-ryokan onsens. Sukayu Onsen looks very worthwhile, as does Aoni Onsen. Definitely something to consider...

I had been thinking about Oosawa Onsen because it is near several nice-looking outdoor baths (Shidotaira, Airinkan, Watari...), as well as Dai Onsen, which should give us a little taste of the onsen town experience.

Do you know if Dai Onsen is nice? (In his book, Neff says that it's one of the few onsen towns he likes, but he also much prefers single-ryokan onsens -- plus the book is getting to be about 2 decades old.)

Also, any thoughts on Naruko Onsen?

I have not been to Dai Onsen. I drove through Naruko Onsen, and the town did not feel very appealing, but I did not check out any baths.

Just a quick follow-up for future onsen explorers.

Unfortunately, we found Hanamaki Onsen as a whole slightly drab. In particular, Dai Onsen's best days were probably already behind it even when Neff's guide was published. On the plus side, Osawa Onsen's rotemburo and nice array of baths is very much worth a stop if you're in the area -- though perhaps not quite worth using up a full day out of our short stay in Japan. Also, it was nice experiencing what felt like a very "local" onsen destination.

Tsuru-no-yu and Hoshi Chojukan were both as great and atmospheric as expected.

The former was spoilt only slightly by what seemed like van-loads of rather ill-mannered Korean tourists. Even as a relative newcomer to onsen culture, I felt quite repulsed the way they washed their faces with their modesty towels and rinsed them out in the water, and even let their empty beer cans float around!