Three years after their adventure, Lafiel becomes captain on the brand new assault ship Basroil and Jinto finishes his training to become a supply officer and joins Lafiels crew. They set out to join a large fleet with the mission of defending the strategically important Laptic Gate from a force 15 times larger than their own. And to bring even more worries, their new fleet commander is from the Bebous family, a family notorious for their "Spectacular Insanity".

Seikai no Senki has been published digitally in English as Banner of the Stars by J-Novel Club since December 17, 2019, and in print as omnibus volumes since February 2, 2021.