Gai sends Shu on a mission to Oshima, where he hopes to find "the rock that started it all." Shu's whole school club gets a free vacation as his cover, but using other people for his own ends still doesn't sit well with him.

Shu's having horrible flashbacks, both to images of his battle with Jun and to other, even more upsetting images that soon have him quitting Funeral Parlor and alienating the people in his life.

GHQ is awash in blood, chaos and song. As the Cancer sweeps over Tokyo, Shu faces the truth about friendship and the consequences of inaction.