Do the Roar!
Both Shrek and Rohan lived alone in a small house. Isolating themselves doing what they want to (Drawing Manga and Ogre things)
Both were assholes until the small dueotagonists (Donkey/Koichi) rocked up to their door and pissed them off. They joined forces to stop the various and oddly similar main villians of their bizarre world.
Kira and Prince Charming- Both Blondes looked after constantly by their parents (Yoshihiro and Fairy Godmother) who went after their someone dear to them (Fiona and Reimi)
In the final act of their (main) stories (not including TSRK and the various Shrek shorts) the villain uses time to fuck with them (Kira literally killing Rohan twice and Rumpelstiltskin making Shrek not meet Fiona)