The Type 97 grenade, or "Kiska" was the standard issue grenade used by the Japanese forces during World War II and is featured in Call of Duty: World at War and Call of Duty: World at War: Final Fronts.
Call of Duty: World at War
In single-player campaign mode, it is possible to pick these up from dead Japanese soldiers in the Marine Raiders campaign. These grenades are not available in multiplayer, split-screen (unless on Co-op) or online, but they can be used in online custom matches if the player selects to play as the Japanese, as online custom matches only allow usage of weapons by country. In-game it functions like any other Frag grenade.