Youto Yokodera is a second-year high school boy and member of his school's track-and-field team with lots of fantasies going on in his head — perverted ones, that is. Unfortunately, he's not good at expressing his thoughts. One day, his equally perverted best friend comes to school suddenly transformed, having rid of his perverted streak, a miracle he attributes to a statuette of a frowning cat. Through further research, Youto discovers that the "Stony Cat" has the power to transfer personality traits on an Equivalent Exchange basis.One day, as he makes his offering to the "Stony Cat", wishing to be more honest with his emotions, he meets Tsukiko Tsutsukakushi, a first-year girl who also wants to make a wish: to be more mature and less overly emotional. Together they make their wish, and the next day they discover that the "Stony Cat" works wonders.All too well.Much to their surprise, Youto became too candid with his thoughts, while Tsukiko becomes completely emotionless. Finding that they didn't like the results of their wish, Youto and Tsukiko work together to find the recipients of their lost personality traits and reverse their wishes. Add to that Azusa Azuki, a second-year transferee who has gained Youto's deadpan facade, and Tsukiko's older sister Tsukushi, the beautiful but stern captain of the track team known as the "Iron King", and you have one wacky melange.Hentai Ouji to Warawanai Neko (The "Hentai" Prince and the Stony Cat in the official English translation by Digital Manga) is an ongoing 2010 light novel series written by Sou Sagara and illustrated by Kantoku, published by Media Factory under its "MF Bunko J" imprint. It also has an ongoing 2011 manga adaptation illustrated by Okomeken, also published by Media Factory in their Monthly Comic Alive magazine, and a Spring 2013 Anime adaptation directed by Youhei Suzuki and produced by JC Staff.For viewers living in the USA, Canada, UK, Ireland, Australia, New Zealand, and South Africa, the anime is available on Crunchyroll under the name Henneko - The Hentai Prince and the Stony Cat.
Tropes found in Hentai Ouji to Warawanai Neko:
A-Cup Angst: Azusa. Youto's attempts to point it out doesn't help much either.
Tsukiko also suffers a bit from this. She starts scratching up Youto's porn DVDs while berating his preference for "well-endowed women", but pauses the moment it's hinted that his taste have changed, and inquires precisely how they have changed. For reference, of course. And in episode 10, she does some "house cleaning" in his room, marking boxes X to dispose of, and O to keep. The boxes marked X have magazines full of busty women, while the box with an O has petite girls on the covers.
All Men Are Perverts: And Youto takes it to a whole new level! He joined the track team entirely because the swimming pool is next to the track, and he does squats for hours as an excuse to peek at all the cute girls in swimsuits as well as cleaned all the floors in the school just so it would give them a reflective shine to look up skirts.
Alliterative Name: Youto Yokodera, Tsukiko and Tsukushi Tsutsukakushi, and Azusa Azuki. It's almost as if Sou Sagara (also alliterative) is fond of it.
All of the Other Reindeer: The reason Azusa transferred to Youto's school. Subverted, as her schoolmates wanted to befriend her but tried to do it the wrong way (pulling a prank on the sensitive Azusa without considering the consequences).
Because You Were Nice to Me: Although Youto's actions towards Azusa does get a bit extreme at times, he does genuinely do nice things to help her out, which causes her to gradually fall in love with him.
Big Eater: Tsukiko, who's frequently seen with various kinds of snacks in hand.
Blood from the Mouth: Played for Laughs in episode 6, when Tsukushi attempts to seduce Youto. Every time she winks at him after saying something suggestive, a sound effect of something heavy being hit plays, and he looks away as if being smacked hard by her words.
Blue with Shock: Azusa in episode 5 while angrily yelling into her phone while waiting for a call from Youto.
Youto in episode 6 when he starts wondering if Tsukushi is attempting to seduce him herself so as to draw attention away from Tsukiko.
Boyfriend Bluff: Azusa tells her two friends in episode 5 that she's totally dating Youto when they ask her about it.
Broken Bird: Both Tsukiko and Azusa have underlying issues, such as wanting friends, which Youto attempts to help them out with during the series.
Also Tsukushi concerning the loss of their parents.
Though in the case of Youto's twin it could be argued that she's just using it as a convenient excuse to not feel guilty over loving him, as, in her own words "Tsukiko doesn't care about the younger Yokodera".
Cast from Lifespan: The cat-god in Tsutsukakushi household brings good fortune to the family, at the cost of their lifespan. Makes you wonder why Tsukiko's parents died in an accident...
Chivalrous Pervert: When push comes to shove, Youto's advances for the heroines are more for their benefit than his.
Cloudcuckoolander: Tsukushi, of all people, is this, once revealed to possess incredibly absurd thought processes.
Club President: Tsukushi to the track and field team of which Youto is a member.
Interestingly, Tsukushi and Mai are prone to this as well. The former stealing his pictures and rubbing up against them later at home, and the latter saying some incredibly perverted things while in the presence of others.
Distracted by the Sexy: When Youto is talking to Tsukushi in episode 6 while she's doing sit ups, her unusual groaning every time she does a sit up causes him to wonder why she makes that noise, and not pay attention to what she's saying.
Driven to Suicide: Played for Laughs in episode 8, when Tsukushi sees Youto near the edge of the school roof. She tells him not to jump, then grabs him from behind and German Suplexes him away from the edge, believing he was going to jump off. He immediately dismisses it.
Dynamic Entry: In episode 6, after Youto inadvertently wishes to see Azusa in her bikini, she pops out of nowhere and falls on top of him.
Equivalent Exchange: The nature of the Stony Cat's personality-swapping powers. To be able to remove an unwanted personality traits, there must be another wisher who wants said trait, and vice versa.
Faceless Masses: Unusually, they sometimes interact with a non-faceless character. In Episode 2, Tsukushi drags some of them, who happen to be truant members of the track team.
Flash Step: Youto does this in episode 8 after spotting Azusa watching him from a short distance away. He then suddenly appears right next to her in the next scene and grabs her to prevent her from running away again.
Forgotten First Meeting: Tsukiko and Youto actually met a year prior to the story's beginning, but she was wearing an oni mask at the time.
Youto has this with everyone in his harem. Episode 12 reveals that as a 6-year old, he sacrificed his memories to Tsukushi in order for her to have had some happy memories with her mother, who likely passed away a short while later. Turns out that he was afflicted with Laser-Guided Amnesia as a result of his wish, and any girl he doesn't stay in frequent contact with, and subsequently becomes a memory to him, causes him to forget.
Freeze-Frame Bonus: During episode 12's Eye Catch, it displays every prominent character throughout this show. If you pause it, you can see that Tsukushi has a body pillow of Youto, while Mai has one of Tsukushi.
Friendly Tickle Torture: Youto does this to Tsukiko to make her overcome her emotionlessness with laughter. And because he's a pervert. It doesn't work, but it does make her bite him in retaliation. He does it again in episode 10 when she tries to hide in his hugging pillow.
Gratuitous English: Some of the episode titles, such as "Goodbye My Home" and "Someday My Family."
Hypocritical Humor: In episode 11, Tsukiko accuses Youto of being a Lolicon after bumping into a young Azusa on the bus. Shortly afterwards however, they run into 6 year old Youto, and Tsukiko immediately rushes at him, and later puts her shirt over his head.
The Immodest Orgasm: In episode 6, Youto and Tsukushi talk while he's holding her feet and she's doing sit ups. Every time she comes up, she lets off an arousing grunt, which causes Mai to come over and accuse him of being a pervert.
Insane Troll Logic: Tsukushi's plan to marry her sister. While she is correct that Massachusetts does allow same-sex marriage, incestuous marriage is prohibited there, as is everywhere else, as other characters point out, and the strained relationship it would cause does not cross her mind at all. Besides, Tsukushi has zero English skills (she can't even write the alphabet).
The second, much larger Stony Cat is even more of an asshole. Tsukiko would like Youto to be closer, so it steals his house and puts all his possessions in a spare room of her Big Fancy House. Episode 7 takes it one step further. It floods the house so they can stay together. Azusa makes a slightly perverted comment and it nearly subjects her to Black Comedy Rape. And when Tsukushi gets upset and rants about how she wants to destroy everything...well, you can probably guess. It wasn't her wish. It was Tsukiko's.
Love Confession: Tsukushi gives a rather awkward and long winded one to Youto at the end of episode 7.
Love Hurts: When Azusa sees Tsukushi kiss Youto at the end of episode 7. She tries to console herself by saying she knew this was coming, and that it's not his fault, but it still causes her to run away.
Lover Tug of War: Between Azusa and Tsukushi (with Youto's arms as the rope) in Episode 6.
Male Gaze: Used quite a bit in the opening credits along and used regularly in the show.
Mind-Control Eyes: Youto is hit with this in episode 6 after Azuza makes a wish where he would play with her belly button.
Murder the Hypotenuse: Played for Laughs in episode 10. When Tsukiko says she wants to talk to Youto about something at his house, he sees her doing some "house cleaning" in his room. He then sees her straddling "Barbara-san", his hugging pillow, and she stabs it, while disemboweling its cotton innards to hide inside of it.
Schmuck Bait: Youto tells Tsukushi that the pervert stuff going on is actually caused by his younger, identical twin brother. She believes it at face value, and this becomes a Running Gag whenever she sees him doing perverted things. He's always shocked that she still believes it.
Unwanted Harem: Youto develops one by the end of episode 7, when Tsukushi mentions that both he and she need a family, and that Tsukiko wouldn't mind just being his little sister. As Youto tries to confirm what she's trying to say, she kisses him.
Wham Episode: At the end of episode 4, Youto's house is missing. Episode 5 reveals his stuff was moved inside Tsukiko's property. And there's a huge Stony Cat in there...
In the end of episode 10, Tsukiko wishes to go back into the past, which causes a bunny speaking in the cat god tone/voice, to grant it. Youto seems to manage to grab her hand right before she disappears, and he vanishes along with her.
Wham Line: Azusa delivers one at the end of episode 7.