The second of the two Tone-class heavy cruisers, Chikuma was specialized for scouting, and had a large compliment of floatplanes. She was designed to carry up to six, but never carried more than five in operation. Laid down in 1935, Chikuma commissioned in 1939, and operated off China in 1940-41. She participated in the attack on Pearl Harbor, and then joined the invasion forces against Wake Island. She then moved south, and supported operations in the Solomons and Dutch East Indies. After that Chikuma remained with the First Carrier Striking Force through the Battle of Santa Cruz, after which she went back to Japan for overhaul. Chikuma next saw action during the Battle of the Philippine Sea, after which she spent some time ferrying troops to Okinawa. Chikuma was part of Center Force during the Battle of Leyte Gulf, and engaged Taffy 3 on 25 October, 1944. Chikuma shared credit for sinking the escort carrier Gambier Bay, and destroyer Heermann, but was crippled by the US forces in return. She was hit by at least four torpedoes, some from aircraft, the first probably from Heermann, leaving her dead in the water. It is uncertain if she was scuttled by the destroyer Nowaki, or if she sank from the American torpedoes, since the destroyer was herself sunk the next day, and there was a lone survivor from Chikuma.