The game text and dialogue are entirely in Japanese .
Monster Hunter XX (Double Cross) is an expanded version of Monster Hunter Generations (known as Monster Hunter X in Japan). It was released by Capcom for the Nintendo 3DS in Japan on . Key Features monster hunter xx double cross 3ds rom jpn link
The easiest legal way is to play Monster Hunter Generations Ultimate on the Switch (available in English). The game text and dialogue are entirely in Japanese
For playing on the Nintendo 3DS, you can find the Japanese ROM through community-vetted repositories or purchase physical import copies. Recommended Sources monster hunter xx double cross 3ds rom jpn link