Yo-san chatters away on the  Maruzen CA870 Setagaya Base Rough Stock Kit in this video. The Maruzen CA870 is a popular choice for airsoft fans, and the stock kit, a limited-release accessory that is currently harder to find than a quiet spot in a busy city. He managed to snag one after a pre-order, avoiding the inflated prices seen on the secondary market. Before diving into the new kit, the video offers a quick tour of the base gun’s current modifications, which include a custom bead sight, a non-binding spring, and a silver port cover that adds a little personality to the hardware.

The unboxing reveals the stock itself along with a special treat: a copy of a hand-drawn design sketch by George Tokoro, the creative mind behind the Setagaya Base concept. The kit includes the main stock body and a distinctively textured cap designed to look like a rough-cut piece of wood. The assembly process is straightforward, requiring only a long screwdriver and a bit of patience to ensure everything aligns without any accidental interpretive modifications to the plastic.

Once installed, the new stock provides a much more secure grip, making the shotgun surprisingly easy to handle with one hand—perfect for anyone who likes to feel like an action hero while standing in their living room. The color and texture match the original receiver so well that it looks like it was born that way. He wraps up the session visibly pleased with the result, suggesting that if you can actually find one of these kits, it is a solid upgrade for giving your CA870 some extra character.