Osamu, Yuma, and Chika who engage Hughes in the upper ranks of the border. However, the upper management is reluctant to join Hughes, who is a neighbor who once invaded Sanmon City and refuses to provide information and has a non-cooperative attitude toward the border. However, Osamu insists on the value of Hughes on the expedition as a guide to the unknown world of the near world (neighborhood). Commander Kido offers a deal on the condition that he takes Chika, who has a huge trion, to the expedition regarding Hughes' enlistment. Osamu couldn't hide his upset, but Chika accepted the conditions with a calm attitude and the deal was concluded. Then, ROUND6, where the B-class high-ranking Tamaki No. 2, Ikoma Corps, and Prince Corps collide, was about to begin ...