Mamoru-kun ni Megami no Shukufuku wo! is a story centering around Mamoru Yoshimura, a young high school boy who gets accepted into a prestigious school for students endowed with the power of Beatrice due to his high intellect. Right after first entering the school on his first day, he meets the mysterious Ayako Takasu, also known as the Beatrice's Angel of Death, who is a pretty and popular female student whose Beatrice powers exceed most others. Moments later, Ayako, who has been known to never show a smile, suddenly confesses her strong feelings for Mamoru, despite having never met him before. That same day, he is brought in as a member of the student council as Ayako's aid as he becomes involved with the dangers and mysteries related to the power of Beatrice.

Notes: The main serialization adapts the story equivalent to the first novel volume. Prior to this serialization, there existed short stories published in the mail-order exclusive booklets Dengeki h and Dengeki hpa, aimed at fans of the Dengeki publication line. Since these short stories are included in the same tankobon volume, they are also treated as part of the "HP Version."

The main serialization in Dengeki hp ran from Vol. 41 to Vol. 45, all published in 2006.

Dengeki h was published in September 2004 and featured the short story "Mamoru-kun ni Manga de Shukufuku wo!!" (A Manga Blessing for Mamoru-kun!!). Dengeki hpa was published in October 2005 and similarly featured the short story "Mamoru-kun ni Manga de Shukufuku wo!" (A Manga Blessing for Mamoru-kun!). The content of these two works consists of original stories not found in the source material.