Hanazono Karin is a normal, depressed girl who is feeling lonely after losing her parents some time ago and after her cat "Shii-chan" had recently died. When at the cat's grave one night, a young boy named Kazune Kujyou approaches her, but she gets angry at him when he calls her a moron, punching him in the face for it. A few days later, Karin meets his cousin, a young girl named Himeka Kujyou and then the ring that her mother gave her begins to glow mysteriously. Note: In the opening, the time was in the future. Karin and Suzune found a Seed of Chaos. After Kazune, Jin and Micchi transformed, they tried to destroy the Seed, but they couldn't destroy it. Rika told that their current power weren't enough to destroy the seed. Karin then transformed and prepared to do Love Evolution with Kazune, but Rika planted the Seed of Chaos into the Chronos Clock. The Chronos Clock became error, and sent Karin into her past.

Karin almost has her ring destroyed in exchange for a fake promise of reviving Shii-chan, but Kazune comes and saves it. After a confrontation between Kazune and the stranger, he agrees to meet Karin the next day to talk about her ring. While Kazune and Karin are talking, Himeka disappears. She comes back later with butterflies, accidentally making Kazune-kun faint.

Kazune starts training Karin, but she has trouble keeping up with his regimen. She begins school at Seiei Sakuragaoka, but becomes depressed when she realizes she does not know much about Kazune or Himeka. Karin cheers up when she meets a cute upperclassman, but is soon confronted by a goddess.

Karin finds a cat in her room that looks remarkably like her dead cat Shii-chan. Kazune decides to investigate. He heads for a suspiciously locked room,and asks Karin to stay away from it. Meanwhile, Karin begins to make friends at Sakuragaoka and Kirio plans his next attack.

Karin learns that if she is one of the bottom twenty on the next test, she's going to be kicked out of Sakuragaoka. Kazune agrees to help Karin study, but she must not only deal with his study sessions, but the Kazune-Z and Kirio as well.