Weapon Shop de Omasse is a rhythm game and so much more.
Unlike other Nintendo-exclusive rhythm games (ie: Rhythm Heaven), Weapon Shop de Omasse's more of a complete experience. Instead of having disconnected rhythm-based mini-games, Weapon Shop de Omasse happens to be a shop simulator that features a rhythm mini-game.
Specifically, Weapon Shop de Omasse is a game that puts you into the role of a blacksmith's apprentice living and working in an RPG. So, instead of being the one who does the adventuring and is at the fore of the action, you see the classic "defeat-the-evil-lord" plot play out from the perspective of a weapon shop.
The game's rhythm element comes in when you work to forge the weapons that you rent out. Aside from that, though, you need to manage your inventory, judge your customers' abilities and needs and give them the appropriate weapon, and work to become a deluxe weapon shop before the evil lord makes his grand entrance.
All of these aspects of the game revolve around your customers. Surprisingly, even early in the game these people are all rather distinct. Even if they're mostly just named "NPC," they all have at least some personality. The way that your interactions with them are presented adds quite a bit to this as well, giving the impression that Weapon Shop de Omasse is filmed in front of a live studio audience.
Out of all the rhythm games I've played to date, Weapon Shop de Omasse is my favourite. However, the premise, the shop management, and the characters are more to thank for this praise than the actual rhythm sections of the game. Truth be told, five customers into the game, these sections have yet to be longer than thirty seconds.
If all of the above sounds good to you, though (and you have a 3DS), head on over to the eShop. As of this writing, Weapon Shop de Omasse is going for $7.99.