Obviously, what draws in the viewers for this series is the ecchi. Admittedly, that is what drew me in. As used up as the whole "ninjas/shinobis" niche has become, I am finding the plot to be fairly enjoyable. As the anime is just over half over, at the time of this post, I will reserve most judgement of the characters.
If you can tolerate ecchi to a certain point, it might not hurt to giv this series a chance. If you LOVE ecchi, this series would come as a great recommendation. But a fair warning for those who DO NOT LIKE the ecchi genre, this series contains large amounts of fanservice.