If you actually mean *coastline* and not towns / cities in the north - I`d recommend looking into the
Echizen Coast (越前海岸). It is absolutely beautiful, and is a designated national park.
I love just driving along the coast. The water is very clear (nothing like the muddy murkiness of the Pacific coastal waters), and great for swimming if you`re there in the summer. In the winter, the cliff sides leading to the water are covered in wild daffodils.
Along the coast there are numerous towns and villages that offer places to stay. (Husband`s family runs an inn up there.)