Nabari no Ou Vol. 13 (manga)

Like her son, Asahi Rokujou was once the Nabari no Ou, ruler of the Hidden World. And ten years ago, a torrent of greed and madness surged through the shinobi realm, with her at the center of the chaos; the memories of the events that came to pass that one fateful day then vanished from the minds of all involved. However, one man—Tobari Durendal Kumohira—retains what was forgotten a decade earlier… The cruel truth he finally shares with Miharu will be the last step on the stairway the new ruler must ascend to assume his throne…