"Dance with Devils: Fortuna" is a supernatural romance anime that intertwines elements of fantasy, mystery, and musical theater. The story centers on Ritsuka Tachibana, a high school student living a relatively ordinary life until she becomes entangled in a conflict between devils and vampire-like beings known as Grim Reapers. The narrative begins when Ritsuka's mother mysteriously disappears, leaving behind a cryptic note that hints at a hidden connection to the supernatural world. This event draws the attention of both devils and Grim Reapers, who believe Ritsuka holds the key to locating the "Grimoire," a powerful magical artifact capable of granting immense power.

As the story unfolds, Ritsuka is thrust into a dangerous game of intrigue and manipulation. She encounters a group of devils from the Shikouin Academy student council, each with their own motives and secrets. Among them are Rem Kaginuki, the charismatic council president; Urie Sogami, a calm and calculating strategist; Mage Nanashiro, a playful yet enigmatic figure; Shiki Natsumezaka, a brooding and intense individual; and Azuna Tachibana, Ritsuka's protective older brother, who harbors his own hidden agenda. These characters form a complex web of alliances and rivalries, with Ritsuka often caught in the middle as they vie for control of the Grimoire.

The plot delves into themes of trust, betrayal, and the blurred lines between good and evil. Ritsuka must navigate her relationships with these supernatural beings while uncovering the truth about her family's past and her own connection to the Grimoire. The series incorporates musical interludes, with characters breaking into song during key moments to express their emotions and advance the narrative. This unique blend of storytelling and musical performance adds a distinctive layer to the anime's presentation.

As the stakes escalate, Ritsuka's choices become increasingly critical, with the fate of both the human and supernatural worlds hanging in the balance. The story builds toward a climactic confrontation, where secrets are revealed, loyalties are tested, and the true nature of the Grimoire is unveiled. "Dance with Devils: Fortuna" combines a compelling narrative with a rich cast of characters, creating a captivating tale of romance, danger, and supernatural intrigue.