Root Letter: Last Answer

Root Letter, stylized as √Letter, is a 2016 visual novel adventure video game developed and published by Kadokawa Games for PlayStation 4, PlayStation Vita, Microsoft Windows, Android, and iOS. It is the first entry in the Kadokawa Game Mystery brand, and was followed by Root Film in 2020. Root Letter: Last Answer, a revamp of the game with additional content, including live-action sequences, was released on August 30 and September 3, 2019 for Europe and North America with an initial release in Asia in December 2018. A live-action American feature film adaptation of the game was announced in 2018 as a co-production between US-based AMMO Entertainment and Japan-based Ammo Inc.