Rakuin no Monshou IV Ryu yo, Fukushu no Souga wo Furue

is the fourth volume of the Rakuin no Monshou light novel series, written by Tomonori Sugihara and Illustrated by 3. It was released under the Dengeki Bunko Imprint in August 2009.

Synopsis
Knowing his brother's tragedy, Orba renews his revenge on his army's general, O'Leary. Virina, who has witnessed the Orba crying, ponders how to treat her, and Ineri, who has doubts about the identity of "Prince Gil Mephius", visits from the Imperial City. Meanwhile, Orba finally begins to move toward revenge. Meanwhile, an army led by Eric, the prince of her neighboring country Ende, advances to Virina's homeland, Gerbera. It was a situation of fighting for the moment until the start of the war. Orba is forced to make a decision as "Prince Gil" and as "Orba himself".

(source: Bookwalker JP - Translated)