Nighthead Genesis: Volume 4
After helping an old acquaintance, the Kirihara brothers are given just the slightest hint more about the mysterious Shouko and what is happening to her. The two then decide to take a short personal side trip and visit family, only to have an old enemy interfere with the reunion.
More is revealed about the players behind all the intrigue, and while diving for information, they are confronted by enemies whom Naoto is deadly serious about protecting Naoya from. Shouko waits for them beyond the battle, ready to tell them one last thing before destiny calls for her.