The JS is a beautiful and alert companion dog that loves its family and therefore is not suited to live outdoors. It has a beautiful white coat that consists of a woolly undercoat and a water resistant outer coat with straight and stand-off hair. The coat needs to be brushed about once a week and if you do not show the dog a bath with dog shampoo is needed about twice a year.
Because of the energic and happy temperament the JS is well suited for both agility and obedience among many other hobbies. Despite its small size it has a big personality and I think it is important to give the puppy a proper upbringing. The JS can be also very stubborn and therefore it has to know its limits already as a puppy. The JS is also a very beautiful show-dog!
The JS is a quite healthy breed in general. If you are looking for a puppy I'd recommend you that the parents should be checked for patella luxation at least, it is quite common hereditary problem with the knees in small dog breeds. Many breeders also do other health checks their like x-rays for hip and elbow dysplasia, heart auscultations and examination for eye diseases.
I recommend mr Marco G. Piasentin's book "The Japanese Spitz" if you like to know more about the breed and its history!
In Finnish you can read more about JS from The Finnish Japanese Spitz Club's site.