In Sleepy Eyes of Death 7: The Mask of the Princess, the masked daughter of the Shogun is named Princess Kiku. She wears a mask to hide her scarred face, which she obtained in a fire that killed her mother. The only person who has seen her face is a samurai named Nemuri Kyoshiro.
Princess Kiku becomes obsessed with killing Nemuri Kyoshiro, as she believes he will reveal her scarred face to others. She sends waves of ninja warriors to assassinate him, but he manages to defeat them all. She then concocts various diabolical schemes and ambushes to try to kill him, but he always manages to outsmart her.
Meanwhile, Nemuri Kyoshiro begins to suspect that Princess Kiku is behind the attempts on his life. He becomes determined to find out why she wants him dead and to uncover the secret behind her mask. Along the way, he meets a woman named Oyo who has a connection to Princess Kiku and may hold the key to unraveling the mystery.
As Nemuri Kyoshiro and Oyo delve deeper into the secret world of the Shogun's court, they uncover a web of deception and intrigue that threatens to destroy them all. Will Nemuri Kyoshiro be able to uncover the truth behind Princess Kiku's mask and put an end to her deadly schemes?