Wadatsumi no Yometori

Kiyonosuke was born an ordinary man, destined to live and die just like any other human being. However, his fate took an extraordinary turn when he inadvertently entered into a marriage with a merman. This accidental union bound him to an unnatural existence, granting him immortality and forcing him to endure the relentless passage of time. For thousands of years, he has wandered through the ages, outliving everyone and everything around him, all because of a single, unforeseen bond forged beneath the waves. Despite the vast centuries that have passed, Kiyonosuke refuses to surrender his humanity. The weight of eternal life has not broken his spirit; instead, it has fueled a singular, unwavering determination. He clings fiercely to his mortal nature, viewing his prolonged existence not as a gift, but as a profound affliction that must be undone. Driven by this desperate resolve, Kiyonosuke dedicates his endless days to searching for a cure to his immortality. His journey is defined by a quiet but persistent struggle against the supernatural ties that bind him to the sea. Until he finds a way to sever the mystical vows of his ancient marriage, he remains trapped between the world of humans and the deep, unable to finally embrace the peaceful death he has sought for millennia.