Light Novel Volume 1

Short Summary
The protagonist, Yōto Yokodera, is a big pervert. Although he wants to live a perverted life, his facade prevents him from doing the things he would like to do. One day, his friend Ponta tells him about the legend of the Stony Cat, which is said to take a trait you don't need and shove it onto someone else. Yōto decides to visit the cat, where he meets Tsutsukakushi Tsukiko, and the two make their wishes.

Although the wish was granted, it is not the expected outcome since Yōto now can only state his true intentions and Tsukiko, who wanted her emotions not to show up easily, has lost the ability to show her emotions. Luckily, they soon find Azuki Azusa, the new possessor of Yōto's trait, and in order to get his false front he somehow ends up as her pet. Although a lot of trouble happens and Yōto receives the title "Hentai Prince", he finally manages to convince Azusa in giving him his facade back.

Shortly after, Yokodera has to explain to Tsutsukakushi Tsukushi, the president of the track team which Yōto attends, also known as the Steel King, why he has been hanging out with her little sister Tsukiko. Sensing danger from the angered King, Yōto makes her believe that it was Yokodera's fictional evil twin brother who dated her little sister the other day.

A little bit later, Yōto has to help Tsukiko as she is getting avoided by her older sister. Yokodera decides that he needs to intervene, and challenges the Steel King to a duel near the Warawanai Neko. There it is revealed that Tsukushi is the creator of the stony cat and that she wants to marry her little sister in Massachusetts.

Plot
The first volume follows Yokodera and Tsukiko losing his facade and her ability to show emotions, respectively, by wishing on the Warawanai Neko. Naturally, they want to get them back, and they decide the best method of doing so would be to find someone who wants to get rid of their facade/emotions and wishes them away. They set their sights on Azusa, whom they discover has obtained Yokodera's facade. Azusa is an ojou-sama character. So, in order to get closer to her, Yokodera ends up swearing to be her pet. The next day, Yokodera and Tsukiko go shopping in the next town. Eventually, they find Azusa working at an animal cafe, evidently not an action a rich ojou-sama would be doing. It's obviously the facade's work that she is only pretending to be an ojou-sama.

The next day, Yokodera asks her out on a date. As he doesn't know the first thing about dating, he takes her to a wedding store and a midwifery place. Tsukiko shows up to save the date, and recommends going to the game center, which doesn't make Azusa cry. Azusa sees Tsukiko as the younger sister she wished she had, and Tsukiko also wishes Azusa were her older sister. By the way, Yokodera wants Tsukiko to be his younger sister, too. Azusa talks about her past, how she was abandoned at the airport at her last school when they went on their school trip, because her two friends told her the wrong spot to go to. Around this point, they are spotted by the Steel King, Tsutsukakushi Tsukushi, who apparently forbids people from having fun, even on  weekends. There Yokodera finds out the Steel King is Tsutsukakushi Tsukiko's older sister. Yokodera grabs Tsukiko's hand and runs away from the Steel King, but knowing he can't possibly outrun the Steel King, hops into a taxi to escape. Away they go, but they soon realize they're abandoning Azusa, so they exit the taxi and run back to the game center. Azusa, who just coincidentally meets her two bully friends from the old school there, thinks that Yokodera has set this up and leaves crying.

Azuki Azusa has been absent for some days from school, thus Yōto decides to visit her. Once there, Azusa refuses to leave her room. Yokodera visits her multiple times, and in the end, kind of kidnaps her and takes her to the Warawanai Neko, where she wishes away the facade, and Yokodera gets it back.

Happy ending there, but Yokodera needs to explain to the Steel King as to his actions that day. He says that... it was his evil twin brother! Which Tsukushi believes. Yokodera accompanies Tsukiko back to her home. The Steel King finds them and promptly thrashes Yokodera, who she deems his fictional evil twin brother.

Tsukiko reveals that she loves her older sister (in an older sisterly kind of way), but Koutetsu no Ou has been rather cold to her as of late. Koutetsu no Ou has apparently been going on about how Tsukiko needs to be more grown-up, thus she made her wish to the Stony Cat. Yokodera decides that he needs to intervene, and challenges the Steel King to a duel near the Warawanai Neko. At the dueling area, Yokodera states that Tsukushi is not fit to be Tsukiko's older sister, and he's more suited to being her older brother. He then wishes away his shame so he can go on and on about Tsukiko's greatness. The Steel King isn't one to lose easily however, and reveals that she's been studying to go to college in Massachusetts, so she can legally marry Tsukiko. Koutetsu no Ou also mentions that she made the Warawanai Neko as a present for Tsukiko. At first, she doesn't believe the Warawanai Neko has any powers, but that changes when Yokodera tells her that Tsukiko's recent change in behavior is due to the Warawanai Neko. Koutetsu no Ou literally threatens the Warawanai Neko into returning Tsukiko's emotions (in the form of a meatbun). Tsukiko, realizing what the meatbun signifies, offers it to Koutetsu no Ou, who gladly accepts and eats it. Tsukiko says that her older sister is actually a really kind person, but doesn't know how to express it.