Just Japanese folk music, really. There are lots of different kinds but generally the difference is minute or non existent but if you want more words with which to search you could throw in other styles or terms. Such as; Ondo, Min'you, bushi, kachāshī, Otemoyan, Shima-uta, Takahata buritama, and Tsugaru-jamisen, should all help with finding results. I personally really enjoy ondo which has a swung 2/2 rhythm and is often used in in parades (I think there is a specific summer festival or something it's used for).