Scarlet Thirst

Every ten months and ten days, Shinto priest Yoichi is forced to butcher a monstrous creature and serve the flesh to the villagers. He's unsatisfied with this life, stuck in a closed-off village, but hesitates to leave and explore the outside world. When his childhood friend, Kyo, returns to the village after Yoichi's father dies, he tries to convince Yoichi to leave and run away with him. But there's a darker secret keeping Yoichi there—one that will change everything between the two of them.

(Source: Seven Seas Entertainment)

Note: Includes the one-shot "Hakujitsu wo Matsu made ni (白日を待つまでに)" and one extra chapter.