X is CLAMP's entry into apocalyptic fiction, blending religious and secular end-of-the-world mythology with its own invented cosmology. The story is set in 1999 and follows Kamui Shiro, a young esper who returns to Tokyo after six years away to face a destiny he can no longer defer: a choice that will determine what happens to all of humanity. Two factions of superhuman warriors — the Dragons of Heaven and the Dragons of Earth — have gathered in Tokyo, designated the site of Armageddon. Kamui must choose a side. His deepest ties are to childhood friends Kotori and Fuma Monou, and fate puts him directly in opposition to Fuma. Kotori's death at her brother Fuma's hands seals Kamui's role as protector of mankind and locks Fuma into his counterpart position. The second half follows Kamui growing into what he is meant to be, while the world accelerates toward its end. The series draws on the visual style of shojo manga and the moral weight of seinen, with acknowledged influences from Go Nagai and Kyokutei Bakin.