It is written by Chihiro Sakutake, with art and cover also by Chihiro Sakutake.

The demon princess Rafi, upon marrying Roren, an immortal knight who protects humanity as part of a new peaceful treaty between humans and demons, did not expect that he would fall in love with her. However, he is quite persistent and continues to try to get close to her, despite his death from the toxicity she naturally exudes. How long will his love last?