Twelve-year-old Ann Uekusa and her mother move to the small town of Shimane, where Ann's grandparents live and everyone seems to be familiar with everyone else. Ann soon becomes friends with Daigo, a young boy who lives in Shimane, as well as Fuji and Shika, Fuji's younger sister and her best friend in Shimane. When Ann's mother, Miwako, commits suicide, Daigo helps Ann cope with the sudden change in her life. They fall in love, but Ann's life can only become more complicated when her estranged father suddenly arrives from Tokyo. After greatly contemplating going to Tokyo to live with her father after he asks her, she decides to stay. Ann tells Daigo about her decision but makes her go anyway. Ann and Fuji both live in Tokyo but hardly ever talk because Fuji goes to an elite high school, K High. Ann met back up with her friends she had before moving to Shimane and they continue their friendships. In Tokyo, she ends up becoming closer to Fuji, which causes conflict between her and Daigo.In Shimane, Shika learns the truth about her parentage and in her confusion, she begins to fall in love with Daigo. When Ann returns to Shimane, Shika upsets Ann's fragile emotional state so that Ann and Daigo will break up. In the end, Ann breaks up with Daigo for fear that her own sadness will weigh him down. Ann returns to Tokyo and starts a relationship with Fuji; however, because she does not love him, the relationship does not last. Daigo refuses Shika and rumors begin to circulate that he is interested in his middle school classmate Ayumu, who has been helping him studying to get into university and become a teacher.Nearing graduation, Ann learns that her father and his friend Kaede Kuroki have been dating and she is pregnant with Ann's half-sister. Ann's father and Kaede marry after being encouraged by Ann and Ann's grandmother. Fuji, now aware that Shika was the child of his mother's affair rather than himself, supports her decision to studying abroad in Vancouver so that she can learn not to rely on others. Daigo and Ann make it to the post-secondary institutions of their choice while Fuji must repeat his senior year after running away from home.After attending her middle school reunion, Ann spends some time with Daigo, where he tells her to find her own happiness. Six years later, Ann meets a young businessman named Keiichiro Sakura and they become engaged shortly after. After Ann learns that he only uses people for his own gain, she confronts him about his insensitivity, but he is disappointed in her and breaks off the engagement. Almost a week afterward, she takes a train to Okayama, where Daigo teaches elementary school. Ann's grandmother, meanwhile, believes Ann will suffer the same fate as her mother. After a failed suicide attempt on the beach, Ann is taken to the hospital and later meets Daigo, who asks her to marry him. She says yes and at the very end the two are shown to be happily married with an infant son named Ryo. Meanwhile, Fuji decides to marry his cousin Mariko (against his family's wishes) and Shiika decides to work for her uncle in America.

A young woman grows up to be a stone-cold assassin after witnessing her parents' murder as a child in Bogota. She works for her uncle as a hitman by day, but her personal time is spent engaging in vigilante murders that she hopes will lead her to her ultimate target - the mobster responsible for her parents' death.

At a museum in Boston, Rugal Bernstein steals three relics: The Kagura Mirror, the Yagami Necklace and the Kusanagi Sword. He uses them to disappear into a dimensional portal to awaken the mythical entity known as the Orochi, which would grant him limitless powers. However, the sword is revealed to be a fake - thus, Rugal's quest is delayed. Mai Shiranui is told by an injured Chizuru Kagura that the whereabouts of the real sword are with Saisyu Kusanagi, who is housed at a mental institution. She is also warned that she alone must defeat Rugal and her boyfriend Iori Yagami should not be involved. At the institution, Mai meets a catatonic Saisyu and his son Kyo, but Iori's presence suddenly breaks Saisyu's catatonic state, and the elder Kusanagi threatens to kill Iori before losing consciousness and dying. Meanwhile, at another hospital where Chizuru is recovering from her injury, she is informed by her colleague Scott that Rugal has altered the King of Fighters database and issued challenges to all fighters around the world. CIA agent Terry Bogard enters Chizuru's room, demanding for information on Rugal's whereabouts and the tournament. She tells him of the different dimensions that exist, but he does not believe a word. Chizuru then tells Terry to go to Seattle and ask Mai, who is actually an undercover operative sent by the CIA to infiltrate Chizuru's organization a year ago. At a cemetery in Seattle, where Saisyu is buried, Kyo and Iori confront each other once again. Iori explains that both Kusanagi and Yagami clans were destined to be enemies. Mai hitches a ride with Kyo to his home, where she explains to him that she is looking for the Kusanagi Sword. Kyo tells her that centuries ago, according to family folklore, a Yagami ancestor attempted to release the Orochi, but it consumed him with murderous rage. Kyo's ancestor killed the Yagami and returned the Orochi into its world. Mai tells Kyo that Rugal is out to unleash the Orochi once again. Kyo, meanwhile, wants to confront Rugal, who destroyed his father's mental state. At a hotel, Mai and Kyo meet up with Iori and Terry. It is revealed that Rugal is using the tournament dimension to merge it with the real world. After Mai blows her cover in front of Kyo, Iori puts on his Bluetooth headset and enters the tournament dimension to confront Rugal. There, he defeats Rugal's servants Mature and Vice in combat, only to have his mind consumed by the Orochi. The next day, Kyo is lured into the tournament dimension, where he first fights Rugal and loses, but is allowed to live as a warning. This prompts him to bring out his ancestral sword and join Chizuru and Terry into the tournament after Mai is dragged in by Rugal. When the four meet up, they are separated into different dimensions, with Kyo fighting Rugal and Mai and Terry facing Mature and Vice. In the middle of a sword fight, Rugal is about to decapitate Kyo when Iori suddenly appears and intervenes. Here, Rugal reveals to Kyo that several years back, he battled Saisyu, Chizuru and Iori over control of the Orochi. During that fight, Iori allowed the Orochi to take over his body, defeating Rugal, but also destroying Saisyu's mental state by bashing his head against a wooden barrier several times. This leads to a fight between Kyo and Iori. Kyo slashes Iori in the back, releasing the Orochi from his body. Disappointed by the outcome of the fight, Rugal sends Kyo, Iori and Mai into another dimension to face them with his full potential. Chizuru and her multiple clones appear, revealing that she has found the mirror and the necklace. The heroes fail in their first attempt to combine the relics and trap Rugal, with Chizuru mortally wounded. Mai takes her place as the mirror holder, but as she, Kyo and Iori corner Rugal, they are once again overcome by his powers. Rugal destroys Kyo's sword, but as he is about to finish him off with a fireball, Kyo magically generates a new sword to block it. He then throws the sword and destroys Rugal. Back in the real world, Scott places a lantern on the ocean in memory of Chizuru. Kyo decides to keep the family tradition by continuing with the tournament. He reflects on his late father's teachings while Iori stares at him from the other side of the pier.

Its a story of a group of teenagers with a shared mysterious past, that are confronted suddenly with the return of a friend who was thought to be dead. After the friend, Yuki, falls ill, they take her to a hospital only to find out it is a labyrinth.