Beckoned by the Festival Music. The Black Relic and the two GAUS units fight to drive a geoframe called the Spider controlled by Efi Dorg officer Mirasa from the urban area. The Spider is stabbed during battle, being forced to retreat and recover. Yukina's class plans for the school's cultural festival and decides on the theme "Teach me about Efi Dorg" since there are three geoframe pilots in the class. The other students build a large replica of the Black Relic through the night, while Kennosuke and Yukina bring food for them on the Cube, which is airlifted back to the research facility by a helicopter of the defense forces. On the day of the cultural festival, Mika encourages Kennosuke and Yukina to try out cosplay, but the two go on to enjoy the various exhibits instead. Efi Dorg officer Muetta attends the cultural festival cosplay competition in her battle armor, which is mistaken for a costume. While a forum for Kennosuke, Yukina and Sophie as geoframe pilots is in progress, Muetta suddenly appears on stage and stabs Kennosuke in the chest with her sword. Kennosuke is stunned to see that Muetta's face looks just like Yukihime.