Kojima posted a photo on his Twitter of these Metal Gear Rising themed umbrella bags, with a print of a katana sheath on them. They will be available at TSUTAYA shops staring mid february. Kojima explained that while an umbrella bag may seem illogical because it’s not the rainy season in Japan, Raiden is ‘Incarnation of Rain’. The umbrella in the photo belongs to Kojima himself.
Below are some photos of (prototype) Raiden masks, worn by Kojima Productions staff members, and Snake himself. These are experiments, so it’s unclear wether they will actually be used as merchandise.
Source: Hideo Kojima’s Twitter