The story is about a ninja named Kagetora, whose job is to teach the arts of self-defense and combat to the heir of a renowned family of skilled martial artists, Yuki. Kagetora falls in love with her, but since a ninja is forbidden to fall in love with his master, he struggles to hold back his feelings. The story deals with Kagetora struggling with his sense of duty and his love for Yuki. Yuki also develops feelings for him later on. However, since it is forbidden for their love to be, how will they react to this? Will Kagetora be able to make it?
- Kagetora Kazama
- Kagetora is a young ninja whose job (oyakume) is to protect Yuki, with whom he is falling in love. Although at first he tries to deny his feelings, he soon comes to realize his true love for Yuki. He has a pet monkey and he has two older brothers who often pick on him. He was slightly pampered by his mother when he was younger, but she also made him stronger. He also is seen to often have low self-control.
- Yuki Toudou
- Yuki is the heir to the Tōdō family and must learn how to be skilled in self-defense and combat. She eventually develops feelings for Kagetora, which she subtly shows to him. She is slightly short, and is polite and charming, although a bit clumsy. During chapter 17 and 27 in volume 4, it is shown that she has better martial abilities when she is drunk, Kagetora thinks so too. At the end of the series she and Kagetora wed, and have two children.
- Akino Kiritani
- Kiritani is Yuki's previous mentor, and she constantly competes with Kagetora. She is skilled in combat and is very strong physically. She is training under Saya Toudou, Yuki's mother. She is very protective of Yuki, like her younger sister. In the beginning, she develops a strong disapproval of Kagetora being her oyakume. Later on, she starts seeing Kujou, Kagetora's disciple.
- Sakuya is Kagetora's childhood friend and fellow ninja. She is skilled in several ninjitsu arts, and vies for Kagetora's affection. She had a crush on him ever since she was little, and is very persistent. Yuki and she have a sisterly relationship that Kagetora does not understand.
- Issei Kujou
- Kagetora's strong-willed disciple. He is often mistaken to be strong and intimidates many with his size. But Kujou is really very weak and lacks martial arts skill. He and Aki start seeing each other later on in the series.
- Nao Takatou
- Nao attends the same high school as Yuki and Kagetora and is the captain of the archery club. When she enlists Kagetora to fill in for an upcoming archery match, the time she spends training with him causes her to develop feelings for him.
- The cute pet ninja monkey of Kagetora. Chapter 0.5 (in Vol. 10) it shows how the two met. Kagetora was in need of a ninja pet. Kosuke and Kagetora connected because, tragically, Kosuke had lost his mother too, and Kagetora came to understand the monkey. They became quick friends and Kosuke agreed to become Kagetora's ninja monkey.
- Another pet in this series, it is the wolf of Shiroumaru, Kagetora's brother. Shiroumaru often forgets about Nachi at Kagetora's hanre at Yuki's house. Nachi is a pup of its mother Shigure, and father Hayate.
- An eagle that belongs to Taka, Kagetora's oldest brother.
- Saya Toudou
- Yuki's mother. She is very strong and skilled in martial arts. She is a teacher for Aki when it comes to Kendo. She is very wise and easygoing.
- Kureha Kazama
- The mother of Kagetora, Shiromaru and Taka. She is mentioned in volume 4 in the episode: The Reason for Smiling. She is also the wife of Tenshuu, and she was a ninja from Hoorai but she could not do her duties because she was physically weak and died while Kagetora was young.
- Tenshu Kazama
- Kagetora, Taka, and Shiromaru's father. He is skilled and very strict. Often on missions so he hasn't seen Kagetora for some years. Until volume 10 when he meets Yuki, after a long time.
- Taka Kazama
- The second eldest Kazama brother. He often teases Kagetora. Taka although has very polite manners to others. He is responsible for Kagetora's fear of ghosts and such. Kagetora often shows a fear of Taka because Taka is most strict on him. He has a pet eagle Kagura, and resembles Kureha Kazama, their mother.
- Shiroumaru Kazama
- The eldest Kazama brother. He and Kagetora have a very close brotherly relationship. Shiroumaru gets a lot of respect out of Kagetora though. He is most daring and knows Taka well. He resembles their father.
- She is a distant relative of Kagetora.
- A kunoichi from Hoorai who claims to be the new "oyakume" to Yuki. She is very skilled but lacks the knowledge of the karate kata, judo.
- She transfers to Kagetora's school in chapter twelve. She fell in love with Kagetora at first sight. Very rich, Transferring from the rich-girls school Fuyoh Girls Academy. Willing to use any means necessary to make Kagetora fall in love with her. A stereotypical princess type, pompous, and a stalker who enjoys hunting Kagetora.
Volume 1: Mission Impossible
Chapter 1: Inappropriate Instructor
Chapter 2: Enemies in Love
Chapter 3: Summertime Attraction
Chapter 4: Peach-Colored Hime
Chapter 5: A Wolf is Coming
Volume 2: A Ninja in Love
Chapter 6: There's No Such Thing as Ghosts
Chapter 7: I'm Not a Kid Anymore
Chapter 8: Christmas Virgin
Chapter 9: A Secret Just Between Us
Chapter 10: Meanie
Volume 3: Forbidden Love
Chapter 11: Useless
Chapter 12: Target: Kagetora
Chapter 13: Lady Tutors
Chapter 14: The Great Escape
Chapter 15: Dangerous Sumival
Volume 4: Family Affairs
Chapter 16: Swimsuit Competition
Chapter 17: Scary Person
Chapter 18: Weak Kagetora
Chapter 19: Reason for Smiling
Chapter 20: New Year's Wish
Volume 5: Sacred Duty
Chapter 21: Rival Wolf
Chapter 22: Cool Guy
Chapter 23: From Kyoto with Love
Chapter 24: Butterfly Memories
Chapter 25: The Person I Love the Most
Volume 6: A Love that Cannot Be
Chapter 26: Kagetora and Aki on a Date?
Chapter 27: How to Spend a Hot Summer Day
Chapter 28: Rainy Kamakura
Chapter 29: Kamakura After the Rain
Chapter 30: Prelude to a Love Triangle
Volume 7:Three's a Crowd
Chapter 31: A Secret Night
Chapter 32: Restless Yuki
Chapter 33: Confession
Chapter 34: A Face Yuki Doesn't Know
side story: Kagetora Edo Version
Volume 8: Brotherly Love?
Chapter 35: Yuki vs. Taka
Chapter 36: Tiger and Hawk
Chapter 37: The Secret of Yuki's Body
Special Chapter 1: Winter Training Is a Dangerous Thing
Special Chapter 2: Yuki on a Date
Special Chapter 3: Beyond the Hot Spring's Steam
Special Chapter 4: Sweet Talk
Volume 9: Three's Not the Charm!
Chapter 38: Aim for the Ninja!
Chapter 39: Want to Protect
Chapter 40: Secret Crush
Chapter 41: Stolen Love
Chapter 42: A Fist and Tears
Volume 10: Love, Ninja Style!
Chapter 43: Report to Mother
Chapter 44: I Love You!
Chapter 45: First Date
Chapter 46: Another Person
Chapter 47: A Good "Oyakume"
Chapter 0.5: Meeting
Volume 11: Over Too Soon?
Chapter 48: One Night Only
Chapter 49: This is an Order
Chapter 50: Together Forever
Chapter 0: Kagetora Beta Version