21st Century Boys As Japan and the rest of the world begins the process of rebuilding after the fall of ‘Friend’, Kenji and his friends must try to uncover the identity of the second ‘Friend’ and other unresolved mysteries. Before the world is once again thrown into turmoil, they must search deep into their childhood memories to find the key to save the world one more time from the threat of ‘Friend’; some mysteries cannot be left unsolved.