Does the Pokemon need to be the same for the Masuda method in X/Y

Yes. The Masuda Method still works in this generation and with Ditto(s/es). In fact, you don't even have to use a Japanese Ditto. So long as one of the Pokemon is from a different region than the other, then they have an increased chance of breeding a shiny Pokemon.

You can chain for shiny Pokemon using the PokeRadar. You have to be careful you don't break the chain. Using repels helps because you won't encounter Pokemon while walking in the grass, instead you will only encounter the ones found with the PokeRadar. X/Y now has grass that will shake, but there might not be Pokemon found in that patch. Stay away from the outer edges of a grass patch, most of the time the Pokemon you encounter will be a different one that you started chaining with. Encountering a different Pokemon will also break the chain. Serebii is showing that a shiny encounter could come around 40 successful chains.

Another feature added to the X/Y games is Consecutive Fishing. Unlike the PokeRadar, you do not need to keep encountering the same Pokemon over and over again. But you MUST be successful in reeling in Pokemon without them getting away. I have been very lucky in the consecutive fishing technique, encountering a shiny around 30-40 successful reels. This can be done with any of the fishing rods. One important note when doing this, DO NOT move from the spot you are fishing in. Once you find a spot, keep fishing there. If you want to increase your chances to get a consecutive fish, get a Pokemon with the Suction Cups ability.

Things that will not break the chain:

• Catching Pokemon,
• Making them faint,
• Running away from battle.
• Using the menu (to move Pokemon around, use items, etc)

I have not tested going into the PSS because there is a possibility it could break the chain if you use GTS, Wonder Trade, etc...