If it has "JPN" language marker on the summary screen, then yes.
Also worth noting that eggs that originate in another language are still considering the language of the game cartridge they originated on. So if I took an egg from my French game, and hatched it on my English game, even though the name is in English, it will still have the "FRE" marker on the summary screen. This Smeargle was hatched that way. Vivillon patterns are the same way, so you can hatch all patterns to have your OT if you get the egg from someone who has that particular pattern.
It was like this in Gen 4 and 5 (and I presume 3).