Chi-Ha-Tan academy is one of the schools that compete in Sensha-do, a school sport that involves tankery. Haru Fukuda, Kinuyo Nishi, Tamaki Tamada and Shizuko Hosomi are having a sleepover to celebrate their change of tactics in Sensha-do. Before, they never wanted to retreat, but now they also learned that retreating can be used as an attack. Fukuda is loud and childish, Nishi is mature and sweet, Tamada is passionate and impulsive and Hosomi is energetic but kind. They all are Japanese.