Rose Guns Days Season 3 manga volume 2 features story by Ryukishi07 and art by Soichiro.

For those I love, I'll pull this trigger.

Alan and Keith have found reasons to keep fighting, even in divided post-war Tokyo. Their work with Primavera's Battalion has given them a place and people who need them. But when a revenge obsessed U.S. Garrison Major arrives intent on disturbing the waters, will Alan, Keith, and the rest of Primavera get swept away by changing tides...?