Takamiya Honoka is a completely average student at Fuyutsuki High School. Up to now, he normally went unnoticed, but it turns out he has a mysterious connection to his classmate Kagari Ayaka, the most popular girl in the school, earning him the wrath of her overzealous fan club.

The prettiest girl in the school, Kagari Ayaka, says her mission is to protect him - since Takamiya Honoka learned this shocking fact, he has been caught up in several incidents. He had no idea why, but in a battle between Ayaka and the Tower Witches, Tanpopo reveals that their target is the "white stuff" inside him.

Since Takamiya became Kagari's apprentice, the two are spending even more time together. Other students are outraged that he's monopolizing their "Princess," but he tells himself it's all part of his training.

Someone in the Takamiya household isn't happy about his relationship with Kagari: his younger sister and fellow Fuyutsuki High student, Takamiya Kasumi. She tailed her brother and Kagari on their date, and grows increasingly irritated by the relationship between them.

Against Kasumi's wishes, Kagari has declared that she will protect Takamiya around the clock. She visits the family to explain this to his mother, who turns out to be an old friend of Kagari Kazane and reveals that the two of them were already betrothed.

Takamiya and Kagari have begun their life together, but they have some weird roommates: Medusa and the KMM Team, who know about the White Princess, Evermillion. Kagari tells Takamiya that their high school security was assured as long as the seals within him were intact, but if Kazane finds out that Evermillion was released, she would most likely seal Takamiya himself.

Hoozuki Kanae, the head of Kagari Ayaka's fan club that protects her from "bad bugs," and Hio Touko, a part-time waitress at a café, have been Ayaka's classmates since middle school.

After Takamiya's fight with the town's delinquent ringleader, Rinon, Kagari decides to resume his witch training. He has been making an effort to work out and toughen up on his own, but it looks like it'll take more time before he can control his own instincts.

Weekend's scheme using her magic bomb has resulted in many Workshop casualties. Worse yet, the Workshop head, Kazane, has lost all her magic power, causing her barrier over the town that protects its citizens to fall.

Delirious with fever after signing the contract with the town, Takamiya strays into a space between dimensions known as "the cycle of recollection." There, he sees the memories of Kazane, the former contractor, including images of himself and Kagari when they were younger.

Weekend has pushed the button to detonate the bombs she rigged up throughout the town. To save the town and its people, Takamiya makes the decision to summon Evermillion, but that would mean giving up his own life as well as Kagari's...