A Free Planets Alliance officer, Murai served in the 13th Fleet under the command of admiral Yang Wenli. He was with the fleet from the very begining, participating in the capture of Iserlohn Fortress in the Fifth Battle of Tiamat: prior to the battle, Murai expressed concern over the amount of trust Yang Wenli had placed in the Rosen Ritter's regimental commander, Walter von Schenkopp.