Lady Ninja Kasumi Vol. 4: Birth of a Ninja is a Japanese original video directed by Hiroyuki Kawasaki and based on a manga series by Jin Hirano. It was released by TMC in Japan on September 21, 2007.
In the movie, AV actress Akiho Yoshizawa takes over the role of the seductive female ninja Kasumi. This time around, her Sanada clan elder asks a former member named Sakichi to help Kasumi with a certain mission, but is quickly turned down.
Kasumi is subsequently sent on this dangerous mission alone, but when she’s captured Sakichi comes to her rescue. Meanwhile, Kasumi settles a score with a particular female ninja rival.