Ryousuke Akiba goes by the alias ES, a codename derived from a mysterious scientific experiment. He is destined to live for at least two centuries and wields unusual mental abilities: he can infiltrate people's minds, uncover their darkest secrets, and even manipulate their memories so that complete strangers regard him as family. Ryousuke’s actions are driven not by malice but by the need to survive, as he wanders Tokyo for reasons known only to himself. No one recognizes his true nature... until Dr. Mine Kujyou, a determined researcher, encounters someone who challenges everything she believes about science—ES, the bearer of the Eternal Sabbath gene. But is he the only one?