The Mika family was destroyed by an army of monsters led by Dark Night Demon General. Nekomaru had two children, but survived after being let go. For his revenge, he recovers the secret sword, Ryujinken, which was entrusted to Mt. There, he meets Nara Genkaku, who orders him to go to Nekomeyama for training. On the way, the Nekomaru escorts and guides the ninja Nekomata Hanbei at the order of the cat god enshrined by the Mikke family. After honing his skills at a swordsmanship tournament, Nekomaru obtains a secret weapon called the 100-person belt as a favor to the deceived Nekoba. Nekomaru finds out that he needs the power of Nekohime, who can read people's minds and predict the future, in order to defeat the Dark Night Demon General. Head to rescue the impregnable Maten Castle ruled by Rashao, a subordinate of Dark Night Demon General.