You will find him on the top roof of the Ninja Academy once you finish ; beat the game.
http://www.actiontrip.com/cheats/ds/narutopathoftheninja.phtml
it's basically just a hide and seek game. Just look for him around the village and you'll find him.
Try looking on www.gamewinners.com to find the answer it is the best game cheats site.
by training
Where cani find naruto gekitou ninja taisen 3?
on my cheats
All the ninja storms and ultimate ninja 3 and 5.
training grounds
that game is the same as ultimate ninja 5. only in diffrent CD's, that's what i know. http://www.gamefaqs.com/console/ps2/code/943122.html
At a store???
I don't think they tell you who Konohamaru's father is. I honestly think it's weird that the 3rd is Konohamaru's grandfather, and Asuma's dad, and Asuma is Konohamaru's uncle... maybe he doesn't have one?
In the forest where you fight Naruto as sauske