Hikawa Sayo

Hikawa Sayo is a first-year student at Keiho Women's University, as well as the guitarist of Roselia. She was a member of both the student council and disciplinary committee at Hanasakigawa before her graduation.

She is the older and more serious twin of Hina.

Background
Ever since they were young, Hina has always bested Sayo in everything, in simple things such as seeing who can swing higher in the playing ground's swings, to more complex things like test scores. Whereas Hina can master new skills with ease, Sayo requires a great deal of information before she can even begin to practice. As a result, Sayo formed a severe inferiority complex towards Hina. One of Sayo's main reasons for starting to play the guitar was because "it was something Hina wasn't doing".

Sayo's intense dislike for carrots also comes from her childhood: Hina was actually the one who used to dislike them, and Sayo would always eat Hina's carrots for her, which then resulted in Sayo getting scolded over not eating hers. Despite her aversion, Sayo has said she can't remember what exactly caused her to avoid them.

Although Sayo and Hina were originally very close, doing everything together, Sayo's feeling of inadequacy caused her to drift away from her twin, until eventually she began trying to shut Hina out of her life entirely. However, as the story goes on, she also begins to try fix their relationship and start understanding Hina more, and is shown to act more kindly towards her, as well as to the other people around her. In one of Sayo's later menu lines, she even almost refers to Hina as someone she treasures before cutting her words short (whereas in the original line, she bitterly said she doesn't have anything to say about Hina).

Appearance
Sayo has slanted green eyes and long, navel-length light teal hair with her forelocks worn behind the ear with a curl on the end. Her bangs are neatly parted with the exception of a single loose lock falling down her face.

Her casual attire is simple with a tomboyish, yet cute tone, mixing pale and dark shades.

Personality
A serious and fussy girl, Sayo can be somewhat cold in nature, even towards those she is close to. She never cuts corners or accepts shoddy workmanship, and is diligent in practice of any kind. She tends to stubbornly deny liking or being fond of certain things, such as fluffy animals or french fries.

In comparison to her sister Hina, Sayo is fairly stiff and sharp, and is highly stubborn when trying to do what she believes is best for others. She speaks formally and addresses most people by their last names, except for her sister and Tomoe, whom she refers to as "Tomoe-san". Like Yukina, she can be prone to make snide or frank remarks, though often these remarks do not reflect how she actually feels. Despite this she is also shown to be prone to falling for weird explanations, especially shown in Beatin' in the Rain.

As the story goes on, especially after she and Hina resolve their issues, Sayo starts becoming softer and showing her kind nature more, as well indulging herself in side activities more often, whereas in the past she would scold Ako and Lisa for wanting to spend their free time on anything but practicing. She is also more willing to extend a helping hand to others, such as shown in the Melody of the Dignified Wind event, where she began giving Touko guitar lessons.

Game Interactions
A list of characters Sayo interacts with in the game (during Lives and in the dialogues at the end of every game).

Etymology
Hikawa (氷川): Hi (氷) means "ice" and Kawa (川) means "river".

Sayo (紗夜): Sa (紗) means "silk gauze, gossamer" and Yo (夜) means "night, nightime".

Trivia

 * ESP Guitars has released a real-life version of Sayo's guitar, M-II, alongside Lisa's bass, and other Bandori merchandise relating to Roselia.
 * Sayo's cool personality is hinted in her name, as "Yo" (夜) means "Night", while Hina's name contains the kanji for "Day" (日) in it, furthering the contrast between the twins.
 * She has the same height as Maya, and is also the tallest Roselia member.
 * She prefers dogs over cats.
 * Sayo loves reading music magazines and in one in-game conversation, was even shown carrying eight of them in her school bag.
 * According to Tae, Sayo has beautiful hands.
 * Though she first denied it, Sayo started playing Neo Fantasy Online regularly after Neo Fantasy Online -Journey-'s event story, where she plays the Tank class.
 * She also got interested in baking after the Cooking Class Craziness! event and often asks Lisa for help.
 * After graduating from high school, Sayo decided to get a driver's license.
 * In the Re:Zero collaboration, her character design was based on.
 * In the Chainsaw Man collaboration, her character design was based on.