I got a japanese growlithe trough wondertrade, so the first thing that I wanted to do, was getting a shiny Arcanine. So the first thing I did was making it a Arcanine and breeding it with a ditto (from my country) so I could get a Arcanine from my country to do the Matsuda method with a japanese ditto, but after a lot (and I mean a lot) of eggs nothing has happend.
So my question is: Can you still do the Masuda method with a Pokemon that has a japanese mom/dad
Edit: Thanks for the help! :3
If I'm understanding you correctly, your Arcanine was bred on your game, and you have a Japanese Ditto as well. In which case, yes that's fine. It makes no difference if the Arcanine's parent was a different language, the Arcanine is in your language now.
But let's clear up some misunderstandings you might have:
Masuda method simply increases the chances of obtaining a shiny via breeding from 1/8192 to 1/1365; there's no guarantee of getting a shiny. You're still going to need to hatch a lot of eggs until you get a shiny.
If you don't want to hatch so many eggs, you can soft reset, which is saving just before you get the egg, and when it hatches into a non-shiny, press the "Home" button on your 3DS and go back to your game and repeat the process.