Seven girls from the Harukawa Girls' Academy are members of the Harukawa Fire Brigade's Student Firefighter Program, which dates back to the Second World War and has been an integral part of the community for years. All of them receive the same training as the older volunteers and respond to the same calls as them, with the only female lieutenants in the brigade, HGA alumni Kana Hoshizora (who also works as a paid firefighter-paramedic) and Masako Yamada (who works as a secretary for the village government), acting as their unofficial mentors.

However, a new principal at HGA wants to abolish the program, much to the chagrin of the fire brigade and many in the community. Additionally, Lieutenant Yamada's marriage begins to crumble all around her. Can the brigade save the Student Firefighter Program? Can Lieutenants Yamada and Hoshizora brave the trials of life in their thirties?