Aritomo Yamagata

General, a former Choushuu clansleader, and the current commander-in-chief of the Imperial Meiji Army and Ministry of War.

Yamagata is a former comrade of Kenshin's, so when they met, Yamagata wished for Kenshin to join the government to honor him for all his efforts during the war.

(Source: Rurouni Kenshin Wiki)