The story of the game takes place on September 2, 2035, when all of Japan is looking forward to the arrival of the astronomical spectacle, the total solar eclipse. High school student Rasu Soma and childhood friend Hakuba Mina went to Hakuba Shrine to watch the total solar eclipse, but suddenly lost consciousness on the way. When he woke up, Cang Zhen found himself in a completely unfamiliar castle. In the process of fighting the monster in the castle, Cang Zhen found that he had the power to turn the monster's soul into his own, but Mina beside him was injured by the monster. Following the advice of the mysterious man Yukaku Genya who suddenly appeared, Cangzhen decides to explore the castle to find a way to heal Mina. Cangzhen met all kinds of people in the process of exploring the castle, and learned that this is the residence of the Demon King Dracula. Although the Earl was destroyed in 1999, Graham, who claimed to be the reincarnation of the Earl, appeared again. Cangzhen decided to use his own power to stop Graham.