Kanazawa

Kanazawa is the most defensible 'hidden Japan' city for a long-stay learner. It was the only major Japanese city untouched by WWII bombing, so the Edo-period geometry survived intact: a samurai district (Nagamachi) where you walk between moss-covered earthen walls and stream-fed pocket gardens, a former pleasure quarter (Higashi Chaya) where teahouses still open into geisha rooms behind lattice screens, and one of the three great gardens of Japan (Kenroku-en) where the yukitsuri snow-protection ropes go up on November 1 each year and become a national photograph. Most of Japan can't show you this without a movie set. Kanazawa just lives in it.

For the language the difficulty is the same as anywhere else in Japan (FSI Cat V, three writing systems, agglutinative grammar with no relationship to anything else you know) but the practice environment is far quieter than Tokyo or Osaka. The Kaga dialect adds a soft imperative -masshi (行きまっし for 'let's go') and a friendlier sentence-final -ke in place of -ka, both gentle entry points to dialect awareness without confusing your standard Japanese. Crucially, locals here do not switch to English the way Tokyo locals will. Partly because they speak less of it, mostly because they actually want you to try. A weekly tutor at Kanazawa University or one of the small private schools around Korinbo runs about ¥3,500 an hour, and a homestay near Higashi Chaya can be arranged for under ¥80,000 a month including two meals.

Costs run about a third below Tokyo for everything except the train ticket in, which the 2015 Hokuriku Shinkansen made cheap and fast (2h30 from Tokyo Station, about ¥14,000 each way). Internet is the same gigabit fibre as anywhere in Japan. The catch is the climate. Kanazawa sits in the Hokuriku 'snow country' belt, gets over two metres of wet heavy snow each year, and runs grey and damp from late November through March. The trade-off is winter Kenroku-en under yukitsuri ropes, Omicho Market crab and yellowtail at peak season, and the city at its quietest, when you can hear shamisen practice through an open Higashi Chaya window on a Saturday afternoon.