Triage X Vol. 18 (manga)

Tobioka City is suffering from a long-term illness that began much earlier than its present affliction. Years ago, Miki Tsurugi was just another friendly, outgoing teenager before her eyes were opened to the darkness taking hold of the city--before she met Yuuko Sagiri. Their first encounter with the city's most ruthless elements brought them within an inch of death...but not everyone was so lucky...