Dies irae: Irasshai Zonnenji

Dies irae: Irasshai Zonnenji was released in 2017 as a promotional ONA, or Original Net Animation, intended to serve as a lighthearted companion piece to the larger Dies irae franchise. The project was conceived as a comedic spin-off, providing a departure from the intense, dark fantasy narrative found in the original visual novel and its subsequent television anime adaptation. By utilizing a chibi art style and focusing on whimsical interactions between the main cast, the production aimed to build community engagement and offer a playful lens through which fans could view the series' otherwise complex mythological framework.

The animation was produced by Genco and handled by Studio Hibari, designed to translate the series' iconic characters into a more accessible, humorous format. Rather than focusing on the high-stakes battles that define the main franchise, this short series prioritizes character-driven gags and meta-commentary, reflecting the lighthearted side of the cast’s personalities. While the main Dies irae works are often noted for their heavy focus on Nietzschean philosophy and grand-scale occult conflict, this specific title was received primarily as a niche offering for dedicated enthusiasts who appreciated the tonal shift and the ability to see familiar characters in a more relaxed environment.