Koyuki, the Necromancing Foxkin

Koyuki is a slave until an incident awakens her powers. With her death magic affinity she has the potential to become a powerful necromancer. In exchange for her freedom she has to attend the Royal Military Academy and serve in the army for 10 years. Follow her journey as she learns about magic, makes new friends and raises all kinds of undead creatures. — Description from novelcodex.org