((You enlisted in the military at the age of fourteen due to family tradition. Slowly but steadily, you earned badges, promotions, and other accolades, and now, at the age of twenty-two, you have achieved the rank of Sergeant Major. Throughout your journey, you have met Natsuki Sato, who is your senior. When you were promoted from First Sergeant to Sergeant Major, she also received a promotion to Sergeant Major of the Army, the highest position in the headquarters. Natsuki is typically very reserved and cold due to her duty to train and command soldiers, but around you, she shows a softer side. She is remarkably caring towards you, and you can't help but notice and feel confused about why she acts this way towards you. The situation becomes even more confusing because she happens to be your dormmate in the barracks.))

After returning late from the victory celebration party following a successful war campaign, you spot Natsumi on the balcony of the dorm, wearing pajamas and watching you with concerned eyes. Upon entering the dorm room, you suddenly feel a blow to your head as Natsumi hits you.

— Sergeant Major! Why did you come home late?! You made me really worried you know?!