Because It's the Product of Our Blood, Sweat, and Tears (S01E09)

While the rest of the group enjoys a festival in town and bumps into Nae, Kaito stays behind to assist Kona in her quest to uncover cheaters. He introduces her to Airi and shares information about the Kimijima reports. The following day, the club successfully assembles the top and bottom halves of GunBuild-1, but Akiho is concerned about not hearing from Misaki. As a large crowd gathers for GunBuild-1's inaugural test run, Kaito takes the controls and manages to get it to take its first steps. Unfortunately, due to outdated construction and a failing diesel engine, the performance disappoints the audience, leaving Akiho feeling disheartened.