My Father is my Captain?!

The story takes place in a small town amidst the flames of war. A year full of abandoned children and dying orphans. Rena, a girl almost only skin and bones refuse to accept death as she got a sister to take care of. When the battlefield is nearing their area, with nowhere to run. Mihcael, a seemingly forever teenager and his team rescues Rena and brought her to base. The problem is, Rena started calling Mihcael "Papa" ever since. How will Rena's future become with her new father and what will become of the world, after the war breaks out?

How will Rena find her other 'Sisters' and their roles will decide her fate.