A notebook of apocalyptic scenarios invented by children for fun becomes the literal operating plan for a real doomsday cult decades later. The book shows that a playful fiction, once documented and remembered, can be treated as a set of instructions by someone determined to actualize it.
A masked leader called 'Friend' orchestrates virus attacks and a giant robot assault on Tokyo that precisely follow the 'Book of Prophecy' a group of boys wrote in the 1970s, forcing the now-adult authors to recognize their own forgotten invention. The perpetrator turns out to be a marginal childhood acquaintance none of them clearly remembers, whose entire campaign is revenge rooted in being overlooked.
The antagonist's power originates in having been ignored and excluded by the central friend group as a child, an injury invisible to the people who caused it. The book presents overlooking someone as a wound that can grow into catastrophic, identity-driven vengeance precisely because the offenders never registered committing it.
Because 'Friend' is hidden behind a mask and symbol rather than a known face, the role can be occupied by more than one person and survives the death of its original wearer. Viewing identity as a transferable public position rather than a fixed individual explains how a movement's figurehead becomes immortal and its true author remains uncertain.