 Features originally intended to be used in "Secret of Mana" or "Final Fantasy IV", also under development at the same time, were appropriated by the "Chrono Trigger" team.According to Tanaka, "Secret of Mana" (which itself was originally intended to be "Final Fantasy IV") was codenamed ""Chrono Trigger"" during development before being called "Seiken Densetsu 2" ("Secret of Mana"), and then the name "Chrono Trigger" was adopted for a new project.Yuji Horii, a fan of time travel fiction (such as the TV series "The Time Tunnel"), fostered a theme of time travel in his general story outline of "Chrono Trigger" with input from Akira Toriyama.