Volume 4 contains Kämpfer 16 through 20. The Cultural Festival is on at the school. Natsuru (male form) is elected to be Committee Member from his class much to his dismay plus his female form was also elected. For the beauty contest Kaede, Shizuku , and the female Natsuru enter as candidates. Later after massaging Shizulu for her participation, Natsuru had do work with a maid cafe in the festival. In the Contest it looked as it was scripted until Akane stormed into it as her Kämpfer self with guns ablazing. Only by intervetion by Shizuku, does the contest end peacefully by knockking everyone else out. Afterward, Shizuku smooches Natsuru which caught him completely unawares. In the end a new Kämpfer appearence is on the horizon into the next volume.