Ryuuko Higurashi

Ryuuko Higurashi(日暮龍虎; Higurashi Ryūko), most commonly known as "Ryuu-nee"(リュウ姉; Ryū-nee; "Big sis Ryuu") is a supporting character in DxD: Twice Critical and another pivotal someone in Takumi's life and adventures. She's the oldest child of the Higurashi couple and Takumi's older sister who took care of him alone since the age of 18. She's an office lady and the main provider for the siblings.

Appearance
An attractive young woman in her mid-twenties, Ryuuko is a fairly tall, light-skinned and dark-eyed office lady of gentle proportions, white bleached hair like her brother's and similar vacant stare, although unlike Takumi's, hers is more on the bored and sarcastic than melancholic.

Being an office lady who works on hours on end, Ryuuko is mostly seem wearing suits and formal wears in black in order to work, and when in leasure, she usually wears loose evening clothes and jean shorts, although she rather stay in only underwear in hot days during breaks.

Personality
Unlike her brother, Ryuuko is easy-going, sarcastic, witty and quite outlandish, but also just as perverted, lazy and bored. Being a genius and a Keio University alumna, her odd and whimsical behavior is only compared to her high intellect, which was the reason why her parents fought for her custody after their divorce, leaving Takumi as a second thought. Despite all her praise, Ryuuko doesn't see herself higher than anyone else and is actually quite blasé and indifferent about it, and in fact is quite jealous of Takumi due to his blandness, which is the main reason why he can make friends, even happily teasing him when he shows interests in girls of his class. She deeply believes in hard work and kindness, and while sometimes she can be quite rude and lazy, and insult people without a second thought, none of her words carry any real weight, and she rarely gets mad at anyone or anything. The reason why Takumi never resented her was because she would only show love and admiration for him.

However, probably her main trait is her compassion: She was the one who took care of Takumi since their parents didn't want custody of him, seeing him as a "expendable child", and raised him at a young age of 18 after graduating college and moving to an appartment away from their parents, being the main provider of the two aside from a distant uncle. She also enjoys Takumi's three best friends, and has earned their respect and admiration, none of them seeing her as a lewd object and calling her a "Super sister". Ryuuko also enjoys the girls around Takumi, and worries about his well-being after he starts working as a Zodiac.

Being always overwork, Ryuuko is prone of some vices, as she tends to drink herself to unconsciousness and more than once slept with a few of her co-workers, both male and female.

History
The eldest of the Higurashi siblings, Ryuuko was considered a genius since birth and became the pride and joy of her parents due to her massive intellect and both academic and athletic performances. However, Ryuuko wouldn't turn out arrogant or alienated by her talents and instead saw them as nuisances as she would rarely interact with her peers due to the special treatment she would receive. Because of that, she formed a deep bond with her younger brother Takumi, and the two would share a special love for each other, even when their parents would show their favoritism only for her.

When the couple decided to divorce and fought for her custody, abusing Takumi so he would choose one of them as their caretaker, Ryuuko decided to take matters at her own hand and, once graduating, she took Takumi and moved to a small apartment in Kuoh, where she would work to provide for both of them and take care of him into his teenage years. It was during that time that she made clear she was jealous of Takumi for his normal life and that he should instead walk his own path instead of being like her.

Trivia

 * Appearance and images based on the Character Leysritt from the Fate/Kaleid Series.
 * Like all Characters in DxD: twice Critical, Ryuuko is named after an animal. In her case, her name contains the ideograms for both "Dragon"(龍; Ryuu) and "Tiger"(虎; Tora); Moreover, her family name, Higurashi, can be read as "evening Cicada".
 * Her nickname, "Ryuu-nee", is also a pun, since it can also be read as "龍王", which means "Dragon King"; a reference of Takumi being the "Perverted Serpent King".
 * Her name also complements Takumi's, since in some eastern myths a snake is only a "prototype dragon".
 * Her name is also a reference to the rivalry between a Dragon and a Tiger, a chinese symbology in which both creatures are considered opposite yet equal forces, such as Yin and Yang.
 * Ryuuko is, so far, Takumi's only relative who's named.