Japanese manga series
 is a shōjo manga series by Yoshiki Nakamura. It takes place in Tokyo, Japan, in the year 2020, revolving around the lives of fourteen-year-old Tsukasa Kozuki as she acts as bodyguard for her classmate, Ryuji Shirogami, who is the third generation boss of the yakuza group, Kuryugumi.
Plot.
It's the year 2020 AD. Tokyo which is a futuristic society, complete with flying skateboards, laser guns and a variety of advanced technology. It is also a city infested with crime with far fewer women than men, with a subsequently higher amount of violence against women. It is also an example of moral decay; the series opens with a girl being attacked in broad daylight with people apathetically passing by, remarking that she should take care of herself.
Not wanting their daughter to suffer the same fate, Tsukasa Kozuki's cop parents raise and teach her to live as a boy. While Tsukasa's parents investigate the murder of her classmate's, Ryuji Shirogami's, father, who is the leader of the powerful Kuryugumi yakuza group, they are both killed in one of the yakuza's in-fights. The deaths leave both Tsukasa and Ryuji orphans, with Ryuji succeeding the group as their third generation boss, known as the Sandaime, and Tsukasa on the streets with her three brothers.
With no other options left, she goes to Ryuji whom she has known for eight years with hopes for shelter. After catching their parents' killer, Tsukasa becomes indebted to Ryuji when her brothers eat a veritable fortune on his tab and he uses the opportunity to tie her into becoming his personal bodyguard until her debt is paid off. Intrigued by her, Ryuji keeps slapping on an increasing amount of debt onto Tsukasa using all manners of ploys necessary to keep the reluctant Tsukasa by his side.
The story mainly centers on the developing romance and relationship between Tsukasa and Ryuji, which has a vast array of difficulties. Tsukasa has dreams of becoming a police officer like her parents, which conflicts with Ryuji's position as the boss of the largest syndicate in the Kantō area of Japan. At the same time, Kuryugumi, as an extremely powerful yakuza group, has many conflicts and gang wars with other groups, making up the rest of the story's conflict.
Tsukasa is the only daughter of two police officers. Upon their deaths in investigating the death of the second Kuryugumi boss, she becomes involved with the next boss of Kuryugumi, Ryuji, who has been her classmate for the past eight years. She was raised as a boy because her mother saw too many women as victims at crime scenes and wanted to shield her from the excessive sexual and violent mistreatment of women. As the child of two cops, she despises corruption and cruelty and wants to be a cop herself one day.
She has an extremely happy and bright personality and thinks that the world is a crazy place, but that she can do her part to make it better. She was trained to fight by her parents and subsequently, at the start of the story, is already an excellent fighter and is rarely defeated in a fight. (She fights with a chain whip that ends in a handle that can alternately be extended into a blade.) Incidentally, she also hates the yakuza, citing them at fault for many of the wrongs of the world.
Although Tsukasa dresses up as a boy for most of the story (she has a chest protector that flattens out her breasts), she is actually a very attractive female with a tall and excellent figure. Hence, whenever she dresses in female clothes and wigs (which she calls it "cross-dressing", since she thinks of herself as a man), she looks much more mature and is often the subject of catcalling and other sexual overtures. Despite this, she is completely clueless of other people's romantic interest towards her, especially with Ryuji. She is also blind to the feelings she develops for him, often confusing her for most of the story.
Tsukasa and Ryuji have attended school together since kindergarten. When she was eleven years old, Tsukasa slipped on a river bank and fell in. Due to hiding as a boy, she never attended swimming classes and nearly drowns. Ryuji, who was watching her from the bridge, quickly jumped in and saved her and performed CPR on her, therefore discovering that she's actually female. Ryuji is thus aware of Tsukasa's true gender from the beginning of the story.
Tsukasa has three brothers: her supposedly fraternal twin, Toshiyuki (14), younger brother, Shohei (13), and older brother, Takuma (16).
Tsukasa later found out that she is the adopted daughter of the Kozukis and that she is actually the daughter of Wakasa Ayabe and the yakuza leader of Hougougumi, which after the deaths of Wakasa and her husband consequently fell apart. Wakasa had given her daughter to her friends, the Kozukis, along with the kagi to the drug, shortly after Tsukasa's birth knowing that she was going to die. Tsukasa finds inklings about her true parentage after Ryuji was shot and in the hospital, and having it confirmed by Wakasa's former bodyguard. Since learning her origins and after Ryuji's been shot, she promises him to stay always by his side (thus, she implies on becoming his seisai).
As the Sandaime - third generation leader - of the Kuryugumi group, he has been raised with the constant goal of succeeding. He rarely shows his emotions on his face and, as long as Tsukasa can remember, has been an excessively gloomy and sober child. Though not obsessive about exacting justice in the way Tsukasa is, he has his own moral code and holds himself to high standards of behavior if not society's.
Though Tsukasa is his bodyguard, she has wondered why he needs one as he is excellently skilled in karate, kendo, judo, aikido, and kyūdō. He is additionally always well-armed (he fought Shiva, Tsukasa's true uncle who had his memories imprinted on a core and survived death, with a knife embedded in his watch) and an excellent fighter, though Tsukasa generally fights the most central battles in the story.
His mother died giving birth to him and he was given over to Toshiyuki Kamojima, a lower-ranked yakuza whose pregnant girlfriend had recently been murdered, to be raised. While his own father did love him, he felt that distance was necessary in raising the next-generation leader and generally kept away from Ryuji in his formative years, leaving Kamojima as his father-figure.
Ryuji is intelligent, cynical, manipulative and in some respects very Machiavellian. However, he is very loyal and does what he can to be kind to the people he cares about, though that is a very short list. Alternately, he is not at all hampered by Tsukasa's naïveté and is fully aware of his attraction towards her from the beginning of the story. He feels relaxed around Tsukasa, she is the only person he has allowed to see him sleeping, and his bodyguard comments to Tsukasa that around her, Ryuji actually looks and appears his young age. He enjoys tormenting and teasing Tsukasa, but under all the teasing does truly care for her to a large extent. It is shown that she is literally the only person who can make him smile and lively in life. It is also revealed that he has had a crush on Tsukasa since elementary school, but was initially disturbed by his feelings when believing her to be a boy until discovering her true gender, much to his relief. Later in the story, after Kamo-san was killed by one of the Ultimate weapons, Tsukasa confronts him, saying that he doesn't need to hide his true emotions in front of her. He then gives into his grief and begins to weep and Tsukasa embraces and comforts him.
Despite his relationship with Tsukasa, Ryuji is engaged to Asago Sumon, the daughter of one of his lower bosses, who has essentially been raised for the role of being his wife. While Ryuji cares for Asago, who is genuinely in love with him, it is in the way that a brother cares for a sister, which Asago does not fully realize until much later. He cares for Asago so much that he always try to protect her from danger; he even takes a bullet, which almost costs him his life, during a dispute with another gang in order to save her. His engagement to her is to prevent clan conflict since the clans under Kuryugumi all accept Asago as an appropriate candidate. Despite his engagement to Asago, it doesn't stop Ryuji whatsoever from pursuing Tsukasa, causing great tension among the three. At the end, he manages to cancel the engagement with Asago and his relationship with Tsukasa becomes stronger.
Ryuji's late father known by his title Nidaime (the second generation) who was killed by Odawara. He was admired much by Kamo-san and Ryuji developed his almost identical look. He made a promise with Kaya regarding her sister, that Ryuji went on to fulfill in his own time, and took personal interest in Kamo-san's intent on getting revenge. He had given Ryuji to Kamo-san after he was released from the hospital, giving him the name 'Ryuji'; the name Kamo-san was planning to give to his own son. His name and Ryuuji's have the kanji for 'dragon' (龍) in them ("Ryū" in "Ryūji" and "Tatsu" in "Tatsuya").
She is Ryuji's late mother and was Tatsuya's seisai. Her existence is finally mentioned in ep. 85. It is left assumed that she died while giving birth to Ryuji.
One of Ryuji's main associates and bodyguards. Kamo-san is the older of the two and has served Nidaime, Ryuji's father as well. He probably knows Ryuji the best out of all the Kuryugumi members and is usually seen with a smile on his face. He would very much like to see Tsukasa and Ryuji get together, knowing how happy the two make each other, and that Tsukasa would make an excellent seisai for Ryuji. Hence, he is determined to find ways to get the two closer to each other romantically, often making observations of the two's interactions with each other and helping them navigate through their growing and often complicated feelings, and to finally admit their feelings for one another. He is a father-like figure to Ryuji, since he had raised him since he was a baby and sees him as his own son. When he dies during the great gang war, his final request is for Tsukasa to look after Ryuji. When younger, he went on a killing spree because Hanawa killed and raped Kamo-san's pregnant wife while recording a video and sell it on the black market.
Bun-san is more serious compared to Kamo-san. He is more of a brotherly figure contrasted with Kamo-san's fatherly nature. He accepts that Tsukasa is very capable of the position of seisai. He greatly lacks skill at using his gun (according to Tsukasa) and is also Ryuji's main chauffeur. He is shown not to be fond of children. He and Kamo-san are one of the few people who know of Tsukasa's true gender and her ties with Wakasa.
' and ', The two younger members of Kuryugumi who get into trouble often. Shigaraki has light coloured hair and has his left ear pierced a couple of times while Muko has dark coloured hair mostly swept back. The both of them do not get along well with each other, even when teamed up, and both shared a dislike towards Tsukasa at first. Mitsugi and Shinji were disowned by their parents before finishing elementary school and were passed around to different relatives before simply becoming runaways at the age of 13. They were picked off the street by Ryuji two years prior to the story and are very loyal to Ryuji.
She was in a relationship with Kamo-san 14 years prior to the story and the two were deeply in love. She was pregnant with his child, a son, and planned on naming him Ryuji. However, she is soon raped and killed by Hanawa, the kumicho of Hanawagumi. She had made a promise with Kamo-san to keep smiling. When Kamo-san is killed and departs from the living world, the two happily reunite in the after life.
Doctor of Kuryugumi's private hospital (inside Kuryugumi's main house). She was ordered by Ryuji to find out