田舎の女子中学生の佐藤・武部・桑手の３人は成績に悩んでいた。
このままでは高校受験が危ない！ということで何とかいい感じに成績を上げる方法を先生に問うたところ、
妙な話を提案された。その内容とは、裏山の妖怪退治をすれば点数を増やしてやっても構わないという事だった。
二つ返事で了承した三人が倉庫から取り出したるは前の戦争で活躍した歩行戦車。
完全に整備したフル装備の歩行戦車に乗り込んだ三人は、いざ妖怪退治に出撃する！

Rural middle school girls Satou, Takebe and Kuwate were worried about their grades.
Thinking "We might not pass the high school exam at this rate!", they asked their teacher if there was a good way to get better grades, and were offered a strange proposition. They were told that if they hunted the youkai on the mountain behind the school, they could earn some extra points on their grades.
The three immediately agreed and dug out a walking tank that was used in the last war from a shed.
After fixing it up and fully equipping it, the the three boarded their walking tank and went out on a youkai hunt!