It was a wonderful morning the Yokodera and Tsukiko went to school together while discussing their plans later than day for the school festival then suddenly a pink-haired little girl showed up, then it accrued that she was Ponta's little sister named Emi. Emi kept calling Yokodera onii-san (big brother) and seemed very friendly with him but at the same time Tsukiko seemed not to like Emi very much and had a feeling that she is a evil-plotted person,then she said that Yokodera should take Emi for a tour of their school and would wait for him afterward for their practices.Emi learned that Yokodera is a well-known "pervert" is his school so Emi took out a Cat-statue-figure like the one found in the storehouse of Tsukiko's house and wished Yokodera would be a "cool" guy in his school.　Weird thing happened, the school suddenly having Roman ancient architecture like the Colloseum, every girls in the school called Yokodera as prince and the school swimsuit as the uniform in the school.

On his way to school while still being bothered by Emi's wishes and existence and Tsukiko's cold behavior towards him, Yōto is informed by Ponta about his rabbit gone missing whilst realizing that Emi's wish of being Ponta's younger sister has been cancelled. At school, Yōto makes up with Azusa as the latter agrees on helping him locate Ponta's missing rabbit. Emi later cancels a wish of having the girls in their school wear swimsuits after she had her swimming match with Tsukiko as she recalls to Yōto of the person she really got along with. Ponta later reclaims his lost rabbit thanks to Azusa's efforts whilst remembering of Emi and Yōto's close relationship, much to Yōto's bewilderment. The following morning, Emi cancels all her wishes after badmouthing Yōto but later discovers that not all Emi's wishes were lifted; their still-Italic school, as Tsukushi reveals to Yōto that she is transferring to Italy.

As Yōto's cancellation of his wish only took a partial effect at his school along with the cat statue's sudden disappearance, Azusa became madly in love with Yōto, much to Mai's nuisance. Checking up on Tsukushi, Tsukushi prompts both Yōto and Mai to make amends before she leaves for Italy but fails. Later, Yōto founds Tsukiko lamenting in his room as she hides inside Yōto's dakimakura but was later found out by Yōto himself. Tsukiko later leaves Yōto's room after knowing that Yōto has met Emi long before her despite her earlier claims that she was the one who knew Yōto the longest. Yōto then found passport tickets to Rome and a letter, sent by her grandparents, both belonging to Tsukiko. Meanwhile, as Yōto takes Emi for a stroll, Emi notices that something's troubling Yōto and tells him to sort it out.

Tsukiko, who along with Yōto, has been brought back ten years in the past by the cat god. As they head to the Tsutsukakushi mansion, along the way they met the younger Ponta, Mai, Azusa, and eventually Yōto, much to Tsukiko's amazement. Shortly thereafter, they meet Tsukiko's mother, Tsukasa, who is brash yet somehow soft towards the younger Yōto, who at the same time badmouths him. Through the younger Yōto, Yōto and Tsukiko were invited for dinner at Tsukasa's mansion, which is at slight disarray. Here, Yōto and Tsukiko discover that Tsukasa's currently living alone and the younger Yōto constantly visiting her to keep Tsukasa company, much to the shock of Yōto and Tsukiko. Meanwhile, Yōto claims that he hasn't remember anything about interacting with Tsukasa, and later, learns that her daughters are currently living at Italy after the death of Tsukasa's husband.

While a sick Tsukasa is being treated by the younger Yōto, the young Tsukushi, along with Tsukiko, agrees to visit their mother once again after Yōto persuades them. At the mansion, the young Tsukushi and Tsukiko wear the clothes their mother made by hand. Knowing that their mother loved them, the young Tsukushi laments over wanting to have memories with her mother. The younger Yōto reprimands Tsukushi, but nonetheless, gives her his precious memories with Tsukasa for their sake by wishing to the cat god, resulting in the current Yōto forgetting all about meeting the Tsutsukakushis and Emi in the past. Meanwhile, Yōto and Tsukiko return to the present. After heading back to the mansion, Tsukushi decides on not going to Italy and afterwards, Yōto and Tsukiko share a kiss. Days later, Yōto, along with Tsukiko, Tsukushi, Azusa, Emi, and Mai have fun at an amusement park.