On a desperate quest to treat his friend's terminal illness, Prince Sirius arrives in a remote village while chasing rumors of a highly potent medicinal herb. The village head helps him to enlist the services of Ombra, a woodcutter who has unrivaled knowledge of the local flora and fauna. Ombra is willing to lend his aid on one condition: the prince must cook and clean for him until the search comes to an end.

Thrilled at even the possibility of success, Sirius eagerly accepts the offer. However, he is unaware that Ombra has no intentions of going through with the arrangement. Ombra immediately recognizes Sirius as the same young boy from his grim past and blames the prince for all of it. Instead of searching for herbs, Ombra spends his days planning how to make Sirius experience the same suffering that he once did. As the prince continues to live in Ombra's remote cabin with him, their relationship takes a complex turn.

Innocent wo Kegasu Kiss was published digitally in English as A Kiss that Stains the Innocence by Shu-Cream, digitally by Tokyopop under the LoveLove imprint on November 13, 2023, and in print on February 20, 2024.