Nin means many things, depending on how you look at it. The kanji of Nin is written in 2 halves. The top half that represents blade, and the bottom half that represents heart or spirit. Some translations are as follows - Stealth, Endurance, Patience, Perseverence, Survival, Endure over mind. Po translates into laws or principals. The kanji on the left says "Nin" and the kanji on the right says "Po"
Now why the image didnt work i have no idea, but here is the link for the image >>> http://www.geocities.com/kage_no_mono/Ninpo.JPG The link doesnt work for some reason when you click on it, but if you copy and paste it in your address bar of Internet Explorer, it should work fine.
this is stupid but when i went to the site i saw the image and exited but when i returned here the picture you posted was up >^D
hatsumi sensei always reffers to ninpo as the higher order of ninjutsu and if any one can help id like the kanji of that as well as the kanji for kunoichi if anyone knows itd be much apreciated
I dont know what Kunoichi looks like in Kanji, but here's Ninpo. If the image doesnt work, its also at http://www.geocities.com/kage_no_mono/Ninpo.JPG
Just found Kunoichi. If the attached picture doesnt show up, you can find it at http://www.geocities.com/kage_no_mono/kunoichi.jpg