Amid a tense standoff between the Krakozhia Dukedom and the Grania Republic, a hero emerges for the people of Krakozhia: high school student Yano Souhei. However, his peaceful routine is shattered when two female soldiers, First Lieutenant Ruto and Second Lieutenant Haruka, unexpectedly enter his life in tanks. The situation escalates when enemy soldier Shachirofu arrives at his doorstep, all of them armed with guns.