Kick-Heart is a love story between Romeo, a successful pro-wrestler, and Juliet, a nun who lives a secret double-life as a female pro-wrestler.

Tomoe Enjou is attacked by bullies from his old school and saved by Shiki Ryougi. He asks her to hide him at her place and admits that he killed someone. Several days later, there are still no broadcasts about the murder as if it didn't happen... and when the victims are found, they're alive and unharmed.

June 1998: After spending two years in a coma caused by a traffic accident, Shiki Ryougi awakens with amnesia. She is visited by Touko Aozaki, a wizard and proprietor of a studio called Garan no Dou. Shiki has lost not only the memory of her accident, but also any real sense that she's even alive. Strangely, enigmatic beings begin to attack her...

The story starts following an incident: a young girl jumps from the top of a building. The image provokes a certain dread, as the girl appears to have been a corpse even before she jumped. The case is dismissed, yet more and more of these suicides occur, and all from the same building. Thus began the rumour, that a ghost inhabited the rooftop of the building.

July 1998 - After a group of delinquents is found dead in their hangout place with all their limbs twisted and torn off, Aozaki Touko receives a request to find the murderer and asks Shiki for help. The main suspect is Asagami Fujino; a girl who was the boys' plaything until recently, who Shiki believes to be "one of her kind".

January 1999: Apprentice mage Azaka Kokutou, Mikiya's younger sister, has been ordered by her mentor, Touko Aozaki, to investigate a certain incident in which fairies steal the memories of students at Azaka's school, Reien Academy. Azaka launches an investigation with the help of Shiki.

In February 1999, a string of murders has Shiki Ryougi and Mikiya Kokutou on edge. These crimes share a disturbing resemblance to a similar set of homicides from 1995, when Shiki and Mikiya first met, and awaken a dark, murderous desire that has laid dormant within Shiki's soul ever since then.

While attending a meeting as a Chief Inspector of the Public Security Bureau, Akane Tsunemori received a report that an incident had occurred on a foreign vessel , and this was the beginning of a big and unexpected case.

In an isolated prison, there are only four prisoners and a cat. One day, a power outage opens all the locks and all of the prisoners are released. However, all of the guards are nowhere to be seen and there are no exits. An extraordinary event occurs in response to an old man's strange behavior.

In Karakura Town, unidentifiable spirits begin appearing en mases. While attempting to deal with these strange souls, Ichigo Kurosaki and Rukia Kuchiki meet Senna, a mysterious shinigami who wipes out most of them. Senna refuses to answer any questions, so Ichigo is forced to follow her while Rukia tries to find out what's going on.