A hidden Ninja village exists deep in the mountain. OKOU (Aimi Satsukawa) who was raised as a lady Ninja is ordered a secret mission by the patriarch.OKOU needs to obtain intelligence about KUROBANESHU, the enemy who is planning to destroy the Ninja Village. OKOU infiltrates into town and carries out a secret investigation on TOGOROU (Ryoichi Yuki), a samurai who is suspected to be the enemy boss. However, the more she investigates about TOGOROU, the more she finds out he is a kind hearted samurai who spare no pains for the neighbourhood. Gradually, they are attracted to each other but find out that OKOU is SHINOBI and TOKOGORU is a member of KUROBANESHU.