Not so long ago we brought you the news that Treasure — best known for brilliant titles such as Sin & Punishment: Star Successor and Gunstar Heroes — is working with Capcom on Gaist Crusher for the 3DS. It's a title that'll aim to combine the in-game action with a broader branding effort, including various toys to accompany the games.

A new Japanese trailer — no Western release has been mentioned to date — shows how additional toys will hook up with the 3DS and affect the game. Though optional, the pictured plastic case allows gamers to attach ""Gai Metals" to their system, which provides in-game gear unique to the toys; away from the handheld the toys transform into neat little figurines. When bolted onto a 3DS, however, it's not the most appealing lump of coloured plastic ever seen, while the trailer only shows the contraption being hooked up to a standard 3DS — perhaps the plastic brace can be adjusted for 3DS XL systems.

You can see the game, and the add-on, in action below. Recent bolt-ons like this and the Pokémon Tretta Lab scanner continue to do the image of the Circle Pad Pro no harm, in comparison.