Inuyashiki is a dark sci-fi psychological manga that contrasts heroism and nihilism through two very different lives transformed by the same catastrophic event, following Ichiro Inuyashiki, a lonely and terminally ill elderly man who discovers he has been turned into a powerful mechanical being after a mysterious explosion, choosing to use his godlike abilities to save lives and seek meaning, while a teenage boy granted the same powers descends into mass murder and destruction, pushing the story into a chilling confrontation between compassion and cruelty, unfolding through shocking violence, emotional vulnerability, and philosophical questions about humanity, justice, and the value of life in a modern society desensitized to suffering, blending grounded realism with brutal sci-fi spectacle and social commentary that challenge traditional notions of heroes and villains, earning acclaim for its mature themes, disturbing tone, and unforgettable contrast between its two protagonists, also known as Inuyashiki manga, Inuyashiki Last Hero, いぬやしき, Inuyashiki Hiro Shishigami, Inuyashiki anime, dark sci-fi manga, cyborg superhero manga, and psychological action manga.