This anime series is centred on Ittoki Sakuraba, an apparently normal school boy who learns that he is the heir to the leadership of the Iga ninja clan following an attempt on his life. He is transferred to Japan's only school for ninjas. Here he finds himself targeted by rivals from the Koga clan, the Iga's centuries old rivals. As the series progresses he makes various friends and learns ninja skills. These involve using special suits that is powered by a special core and gives the wearer increased fighting powers. Inevitably there is plotting, betrayals and fighting.
When I started watching this I had fairly high hopes but soon felt a bit disappointed. Ittoki isn't a particularly interesting protagonist. He is clearly meant to come across as an ordinary boy who gradually learns what it takes to lead but instead he is a bit irritating and quite forgettable; as I'm sure this series will be soon after one has finished watching. The ninja suits may have been an original idea for the ninja genre but they proved less interesting that the unique supernatural powers used by ninjas in series such as 'Basilisk'. The character design and animation is decent enough. Overall I'd not call this a must see; if you want to see Iga versus Koga action watch 'Basilisk'.
These comments are based on watching the series in Japanese with English subtitles.