A family drama which goes over three generations. From the Battle of Jaburo in Universal Century (U.C.) 0079 to the battle with the Crossbone Vanguard in U.C 0123. Kamuna Tachibana who grows from a green 21 year old ensign to the 65 year old Veteran commander of the frontier side. In the middle of fighting the Vanguard, he notices that the commander of the enemy MS forces is none other than his son Syun. Wondering where he made a mistake, Kamuna looks back to the past and tries to find an answer.