"MARS RED" is a sound theatre that is originally written by Bun-O Fujisawa. It all started from a sound theatre that is now developing into a media franchise since the Reiwa era. This is the new world of "MARS RED" written by Bun-O Fujisawa exclusively for this game.

Early twentieth century, Japan - the flowering era of Taisho influenced by Romanticism. As the nation prospered in modernization, some species were outcasted and stood at the crossroads of their lives. They were - vampires. Although they possessed superhuman physical abilities, they would burn under the sun and only lived off of blood. They suffered from having keen senses, and most of them could not adjust to their eternal life. Thus - they were vulnerable species. This is a story about a young man named Yatsufusa, who became a vampire against his will and seeks the meaning of life as he encounters different people and species surrounding him.