Tales of the World: Material Dungeon (テイルズ オブ ザ ワールド マテリアルダンジョン Teiruzu obu za Waarudo: Materiarudanjon?) is a spin-off game released on January 31, 2008 in Japan only for mobile cellphones (NTT DoCoMo FOMA 900i). The characters are designed by Yuu Shiina, who has not worked on any of the Mothership Titles in the Tales series. The characteristic genre of the game is "Outfit Change RPG" (着せ替えRPG Kisekae RPG?). The protagonists are Rio and Rene, who are accompanied by a small cat-like creature named Klotho. The game's battles take place on the same screen with tile-based movement, along with a costume system akin to the Narikiri Dungeon games.