How often are games from Naruto Shippuden: Ultimate Ninja Storm series appear on site?

rarely

Here's a link. Look at the "giveaways" section.

https://www.steamgifts.com/giveaways/wishlist/search?q=Naruto

Edit: CptWest's link is much better. I didn't know there was an archive feature.

you could check the archive for whatever game you want.

Here's a link for Naruto
https://www.steamgifts.com/archive/search?q=naruto

https://www.steamgifts.com/archive/search?q=Ninja%20Storm

The archives, as suggested by other. Just heads up that it doesn't allow you to go past page 100 for any query (or no queries) regardless of the total number of GAs.

i don't know how often - i was going to say something about you being just another leacher but saw your two giveaways so thanks have a white list place - just keep checking on the whish list section i would guess