Birthday: August 26, 2000
Gender: Female
Age: 17-18
Blood Type: B
Height: 160 cm (5'3")
Eye Color: Brown (manga), Blue (anime)
Hair Color: Brown (manga), Black (anime)
Occupation: High School Student, Karaoke staff (part-time), Rental Girlfriend (part-time, former)
Affiliation: Karaoke Village, Maple (formerly)
Favorite Color: Blue

Ruka Sarashina is a supporting character and occasional minor antagonist of the Kanojo, Okarishimasu series. She is a girl whose heart beats slower than the average person and she seeks a lover that will help her cope with her condition.

Ruka's most identifying features are her short black hair and blue eyes tied up with a ribbon, usually a blue one. With her ribbon off, her hair is a voluminous layered bob. She's often in her school uniform, which consists of a white button up with a tie, a blue blazer and a hiked up skirt. During her rental dates, she usually wears a turtleneck sweater with a variety of patterned short skirts. Her casual wear usually consists of sundresses, though she wears longer sleeved clothing and leggings when dressed up for conservative occasions.

Ruka has a womanly figure that belies her youthful appearance. Although she personally admits her figure isn't as filled out as Chizuru's, she is described as having a sizable bosom and long, slender legs. She is considered very attractive, often comparatively with Chizuru by the male characters, and tends to gather a lot of attention when in public.

Ruka is described to be a cheerful, determined, and passionate girl. She is a straightforward person who is honest with her feelings. On the flip side, her traits often convey her as being self-centered, pushy and possessive. This personality of hers developed after learning of her condition and being alienated from her peers. Because of this, she became very fixated on the idea that getting a boyfriend would help her in having a faster heartbeat.

Ruka's brash persona often leads to conflicts with Kazuya and, more specifically, Chizuru. On top of that, her determination can lead her to being stubborn to a fault. This often leads to her making poor decisions to get what she wants, and she will often throw tantrums or act out if things don't go her way.

Ruka is born with an irregular heartbeat, leading her life to be tormented for being treated differently from the others because she can collapse if she performs a hard working activity. This leads her to become a rental girlfriend as a wish to have someone who can make her heart beat faster without any trouble. For a while, all the people she met with had no effect on her, until she met one who was truly genuine during a coincidental meetup, Kazuya Kinoshita.

The sincerity of Kazuya made her fall in love with him and slowly led to her decision to quit her rental girlfriend job. She technically blackmails Kazuya into being her "trial boyfriend" under the condition that she does not reveal Chizuru's job and her relationship with Kazuya. Unfortunately, this causes her to become a thorn on Kazuya's side. To make the matter worse for Kazuya, she now works at the same job as him.

(Source: Kanojo, Okarishimasu Wiki)