As translated by GaijinHunter, the game is due for Japanese release on March 18, and will include a G-rank difficulty level, a new Airship-based hub village, several returning monsters (including Barroth and Barioth), new Deviant versions of monsters (including a Deviant Diablos) and at least one unnamed new monster.
XX also adds two new Hunter Styles – one that rewards players for playing aggressively, and another that wasn’t shown, but appears to favour using barrel bombs – and adds some version of Hunter Styles to Generations’ Prowler hunters.
Players of X will be able to import their save data to the new version, and those who played Monster Hunter Stories will also see some benefit.
worked for me !