Prima Doll: Ceremony of the Unknown

Story about Houkiboshi's past. Due to Ouka's rampage, the battlefield is dominated by mechanical dolls. Nameless Imperial Army soldier secretly infiltrates into enemy ranks for a certain purpose. In destroyed urban area with no survivors he meets a support doll Houkiboshi who miraculously escaped the rampage. The two of them join hands and try to escape from this hell, but will they be able to? [Translated from official site]

Due to Ouka's rampage, the battlefield is dominated by mechanical dolls. There was a nameless imperial soldier who secretly infiltrated the city for a certain purpose. In a city where there are no living beings, he meets a support doll Houkiboshi who miraculously survives the outbreak. The two will try to escape this hell hand in hand.