As the day of Gravi and Procella's joint concert approaches, the spirits of all members are on the rise! Though amidst all of it, only Gravi's leader, Hajime, has glum look on him. While his unit members seem to get worried of him, who is very busy with not only his duty as the unit leader, but also with solo jobs, it seems those aren't the only reason behind his low spirits... The one that Haru, his partner, and Kai, a fellow senior member, chose to become someone that Hajime can consult with is ―― obviously, none other than this person. The elegant yet lazy leader of Procella, the White Demon Lord: Shun.