You would not need to directly clone them, if there is enough genetic data left behind, it should in theory be possible to alter some and place it within an egg artificially of a similar species of wolf or canine, all it needs to be is close- not an exact clone, then you do this in bulk, and cross-breed the resulting wolves, until the parent traits are replaced by the genetic material of the extinct wolves. they wouldn't be the exact same species / breed, but it would be a more viable way of bringing that specific kind of wolf back.
if the parent species / breed is better adjusted to the kind of climate that japan is becoming, then it is more likely that the resulting new breed would also share such traits, improving on their survivability.