ASH: Archaic Sealed Heat is a 2007 tactical role-playing game developed by Mistwalker and Racjin and published by Nintendo for the Nintendo DS exclusively in Japan. The storyline follows Aisya, princess of Millinear, after a fire monster burns the kingdom to ashes on her coronation day. She gains the ability to revive the dead as ash-formed bodies and sets out to investigate the cause behind the disaster. The gameplay combines tactical grid-based movement of 2D characters in the field with traditional turn-based battles, in which party members are represented by CGI models.

Mistwalker Corporation is an American-Japanese video game development studio. The company was founded in 2004 by Hironobu Sakaguchi, best known for creating the Final Fantasy series. The company has created both game franchises such as Blue Dragon and Terra Battle, and standalone titles including Lost Odyssey (2007) and The Last Story (2011). With the financial problems caused by Final Fantasy: The Spirits Within, and his growing dissatisfaction with management, Sakaguchi decided that he wanted to make games outside Square. Mistwalker's first two titles were Xbox 360 RPGs; Blue Dragon (2006) and Lost Odyssey. Following The Last Story for Wii, Sakaguchi and Mistwalker changed to focus on in-house mobile titles. The original Terra Battle saw widespread success and acclaim, leading to further mobile projects.