It's covered in the first 10~20min or so of the game, and is really a minor side point. Off topic, put P5 as a game doesn't really care about spoilers much, th

It's covered in the first 10~20min or so of the game, and is really a minor side point. Off topic, put P5 as a game doesn't really care about spoilers much, there is one specific story telling gimmick that will screw with you if you're really sensitive to these kind of things.