Old-time Kairosoft fan here. As a rule, all of their games have a grind element. You’ll find it’s here, too, but it can be somewhat mitigated through the use of gems. You might see this and feel the urge to delete the game, thinking it’s just another money sink. I’d urge you to hold back in this particular case. Gems are very easily earned in this game as you play. As long as you don’t spend money on the Gacha feature on the bottom left, which you do not need at all to experience what this game is at it’s core. They do give free Gacha tickets from time to time, which I highly encourage using.
It’s deceptively simple at first. But as you progress, you’ll find more features than in any other Kairosoft game. It has elements of a town builder, dungeon crawler, and management sim, all executed with enough skill for you to appreciate it.
All in all, I love this game. I’ve sunk hours into it and I’ve barely scratched the surface. If you like Kairosoft games and you already have Apple Arcade, just get this game. You’ll feel at home immediately.