Question about the Real Estate and Cabaret Club mini games

[javs]

Right now i'm in chapter 7 and I've just unlocked the cabaret club mini game for Majima. I've noticed that both this and Real Estate Royale are really great ways to earn money so I plan on fully utilizing them. However, I was wondering if these minigames are essential to completing the main story and also if I'll be able to continue working on them in premium+ mode.

[Deathraven13]

No they are not important for the story, yes in premium mode you have them.

[David Young Henning]

Outside of earning a ♥♥♥♥-load of money fully completing the Real Estate/Cabaret Club side quest chain unlocks you something really cool for each character.

[punchtig3r]

you'll be really glad that you completed both of them when you see what it unlocks :D

[Gale Erick]

Also, for each rival you defeat you unlock a certain block on your ability grid.

So yeah if you want to max out your skills doing these business stuff os necessary.