Our protagonist Hiro created Team BRIGHT along with his friends when they were in elementary school. The team attracted much attention, especially armament specialist Sota, but their Gunpla (the 78) disappeared on the day before the tournament, leading them to quarrel and split up. Now, four years later, the former group record-keeper Imaizumi sends the other members a video and they meet at their old school. However, Imaizumi isn't there, and Hiro and his friends find something else instead...