Cost for electric power for operation of a light emission portion is restricted and electric power can be supplied also to a gun body. In a light emission device mounted to a gun body to emit light toward a target, a device body comprises a power supply composed of a light emission portion and a charging-type battery, and a control unit that controls emission of light, and the device body engages with option mount portions, which are provided on the gun body, to be fixed thereto by a fixation device with an optical axis of the light emission portion made substantially in agreement with a firing direction of the gun body. The device body comprises a connection terminal that can be connected to a terminal on a battery charger side, the connection terminal can serve also as a feeding terminal that supplies electric power to a toy gun from the charging-type battery, and the connection terminal can be provided in a male and female fitting type in a manner to enable the terminal on the battery charger side to be connected to an outer surface thereof.