Here's the thing: the Japanese aren't as big on werewolves as we here in the West. You'll get werewolves turning up as supporting characters in vampire books (and trust us, we'll get to those!), but for the most part, werewolves in the traditional sense just aren't there. Of course, the Quileutes aren't exactly werewolves in the traditional sense either, so that makes things much easier for us!
For your shapeshifter needs, it would only make sense for us to recommend one of the most popular manga ever published (both in Japan and America).
Fruits Basket by Natsuki Takaya tells the story of Tohru Honda, an orphan who lives with her grandfather. When she needs to find some place to live while his house is being renovated, she gets taken in by the mysterious Sohma family-- the boy Yuki being the one all the girls at school want.
But while the other girls seethe with jealousy over Tohru's new living arrangements, she finds herself entrusted with keeping the Sohma family secret-- they are shapeshifters, each one possessed by one of the spirits of the Chinese Zodiac. They transform into their animal when touched by a member of the opposite sex (which, to say the least, makes the prospect of dating a difficult one).
Things get even more complicated when she meets Kyo, the Cat of the family. In the legend of the Zodiac, the Cat was tricked by the Rat into missing the Emperor's feast where they were given their status. Tohru had always felt affection for the Cat in the legend, and her feelings for Kyo soon take a similar turn. However, he's too busy picking fights with the Rat--none other than Yuki!-- to notice.
Tohru may have found the family she's always wanted, but will she find something more?
Fruits Basket is rated T for mild violence and sexual innuendo.