Tsukiko Tsutsukakushi

Tsukiko Tsutsukakushi is the female protagonist of the The Hentai Prince and the Stony Cat light novels and related works. She is Tsukushi's younger sister and referred to as younger sister by Yōto. Her rival is Azusa Azuki and their tension between each other is intense.

Appearance
Tsutsukakushi Tsukiko has a small nose, slender shoulders and arms, a delicate chin, petal-colored lips, and fair skin. Tsukiko's bangs are held back by a pale pink hairpin as well as a bright pink bow on the right side. The rest of her shoulder-length light grayish hair is tied up in a side tail to the left. She has warm grey-blue eyes. Apparently she's very flat-chested and rather short as well, since she was once mistaken as an elementary grade child. She can mostly be seen wearing her school uniform, which consists of: A white buttoned up t-shirt with a yellow ribbon on the collar, two green leaves patterned on the collar, and light pink buttons on the cuffs and on the front of her chest, a red tartan skirt, and black knee-length socks with light brown shoes. Outside of school Tsukiko is usually seen wearing lolita-style clothing.

Personality
Tsukiko is an extremely shy person, who thinks of herself of being to childish. After she has prayed to the Stone Cat, her emotions aren't noticeable any longer. Apparently she likes eating as she devours snacks and other stuff all the time. It is often hinted that she has feelings for Yōto, but cannot express them since she has lost them to the Stony Cat. Every time Yoto acts too perverted with Tsukiko, she habitually bites him to stop him from doing anything perverted towards her.

Past
She and her sister were once close to the point that they took baths together. However, their relationship became estranged when her sister started avoiding her.

Before the start of the series, she once met Yōto who once gave her advice on how to get along with children before she went to high school. Also in the past, she wore a devilish looking mask so that people could not see her emotions. However, she soon returns to her old childish self.

The Legend Of The Stony Cat
She first appears in the series when Yōto makes his wish to the stone cat where they both make their wishes together. Her wish to the Stony Cat is not to show her emotions so easily, because she is a crybaby. As a result, she becomes unable to express any emotions whatsoever.

The Fairy Doesn't Get Mad
Tsukiko feels jealous when she sees Yokodera and Azuki Azusa together and follows them around on their date. It shows she's very skilled at the crane machine, and that the Steel King is actually her sister.

Yōto Yokodera
The first time the two of them meet on the hill of the neko statue, Yōto is mistaken as a dangerous person as Tsukiko thought of his hug pillow as a corpse. After they meet once again in school, the two of them swear to help each other with getting their "lost things" back. It is likely that she has fallen in love with Yōto as she is always happy when Yōto statess something which might be interpreted that he loves her. She also went to the bounds of wishing to the stony cat to have sa dangerous weather only around their house to force Yōto to stay by her side to become her "big brother". However, Yōto denies her request.

Tsukiko has a dream and remembers that Yokodera was the person who gave her advice on how she could get along with children. However, Yokodera who gave away his memories, could not remember. After traveling back to the point where Yokodera gives away his memories, she decides to stay in Japan fearing that Yokodera might forget about her if she became a memory. In the end, they both fall in love with each other, and seal it with a kiss.

Tsukushi Tsutsukakushi
Tsukiko was once very close to her older sister. However, she believed that Tsukushi was not talking to her in her teenage years because of her emotional/childlike attitude. It turns out that Tsukushi has problems conveying her feelings. Tsukushi actually loves her little sister and even wants to marry her in the US. Tsukiko ends up giving her emotions, which is stored in a meat bun (due to the Nekogami), to her sister so that she can convey her feelings openly. For the remainder of the anime, Tsukushi openly dotes on her little sister.

Azusa Azuki
Tsukiko respects Azuki as her senpai, yet does not like it when Azuki gets too close to Yokodera. It's seen in the Novels Azusa and tsukiko become close and soon live together, and get along like sisters.

Quotes

 * 'Remember what you said before? That you'd become my brother. Does that still apply?'
 * 'Worthless? Just, you say? Since I'm just the worthless old me, I considered possibilities like your memories being altered. Those seem to have just been worthless worries on my part.'
 * 'Help... help! There's some weird girl in the kitchen. I was making rice porridge, but she keeps eating it like there's no tomorrow. Who is that girl?'
 * 'Words... words mean nothing. A number one deserves the privelleges of a number one. There are some things that must be expressed through action, not just words.'
 * 'Then I shall announce my judgement: You are totally, utterly and completely, even at the very last second of the very last scene of the very last episode, a hopeless pervert.'
 * 'I'm not tasty at all.'

Trivia

 * Tsukiko mentions that she had the lowest numbers in her class for the body measurements.
 * Tsukiko's voice actor, Ogura Yui, is the singer of the anime's ending "Baby Sweet Berry Love".
 * Tsukiko's CV and Azusa's CV are the two members of the duo YuiKaori.
 * On the first light novel's cover, her shadow takes the form of a cat. This is likely a reference to how Yōto refers to her as a cat, as she is expressionless.
 * Tsukiko is extremely weak to alcohol. Getting drunk just by its scent.
 * Tsukiko's name (月子) means "Moonchild".
 * She made an appearance on The Daily Show with Jon Stewart 9 December 2013 who put up fan art of the NROL-39 Octopus attacking her. Stewart would later hypocritically condemn laws allowing erotica of minors on 20 June 2014, even though the previous year he was involved in disseminating it.
 * Her favorite colour is pink.
 * She's into sweet lolita fashion.
 * She wishes to become an idol.