Your days begin before dawn at a remote fortress along a separation wall built to protect the country from a mysterious disease. For two years, your routine has been little more than waking before sunrise, patrolling and firing warning shots from a machine gun, eating rations and going back to sleep. That routine changes when Kasumi Satani, a woman in need of rescue, escapes to the fortress and is taken in under your protection. Despite being the one in need of shelter, Kasumi insists onn taking care of your health, bringing an unexpected warmth to an otherwise isolated existence, turning life at the fortress into something livelier.