A young girl named Kanata Sorami joins the army with the hope of learning to become a good bugler. She is assigned to a place called Seize, which is currently holding a festival where people splash each other with water. She is found by her superior, Rio Kazumiya, who gives her a bath and tells her about the legend of the Fire Maiden. While looking at a bell owned by Rio’s father, an owl steals it, forcing Rio to stop Kanata falling off the balcony trying to get it. As Rio participates in the festival, Kanata decides to search for the bell. She finds it hanging off a ledge, but when she goes to get it she falls into the lake, where she sees the golden skeleton of a winged creature. Stranded at the bottom of a canyon, she plays her bugle where she is responded to by Rio on her trumpet. She takes her to the Time Telling Fortress and plays the trumpet as the sun rises, introducing herself as Kanata’s bugling teacher.

During breakfast, Kanata is introduced to the other members of the 1121st Platoon; Felicia Heideman, Noel Kannagi and Kureha Suminoya. Kureha shows some hostility towards Kanata, but she is assigned to show her around the fort. When Kureha takes Kanata to see the tank of the squadron is kept, which is in the process of being repaired, Kureha expresses her depression because the military often ignores the squadron’s existence. Later that night, Noel and Kanata claim they saw a ghost in the barracks, so Kanata and Kureha are sent to investigate. They learn the place used to be a school. Kureha laments that their platoon is in the middle of nowhere and is generally ignored. The two are surprised by an owl, the same one that stole Rio’s bell, but with Kureha’s help they manage to capture it. They decide to keep it and name it Shuko.

The group give Kanata her paycheck early and she goes into town to spend it. In actuality, it is to get her out of the way whilst the others illegally trade some calvados to make some money. When they get word from Naomi that some investigators are planning to snoop in on the deal, they stage a mock shoot out to scare them off. Meanwhile, one of Yumina’s orphans, Mishio, runs off when she objects to having her hair brushed. Kanata finds her at the market, where she reveals she is looking for a certain box. Yumina explains to Kanata the box was a memento of Mishio’s mother that was taken when she died. Mishio ends up on a roof, but the noise from the mock shoot out causes her to slip. Kanata manages to save her before she falls, though it causes some rocks to fall that smash into the investigators’ car. While apologizing to Naomi, they notice the box Mishio had been looking for. Mishio decides to give it to Yumina as a symbol of how much she cares for her.