Suruga, the main character of Suruga Monkey, is Koyomi's underclassman, star of the school's basketball team and one of Hitagi's acquaintances from back in junior high school. She is so well known in her school that not a single student had not heard of her, mostly because it was her who was responsible of the rapid rise of success of the school's girls basketball team due to her talents. She considers herself a lesbian, fujoshi, lolicon and masochist. Her hobbies include reading yaoi literature and playing basketball. Although her sexual preference is clearly towards females, she does not have a hard time interacting with males, and she even manages to say teasing remarks when she is comfortable with the person she talks to (i.e. Araragi).
Suruga is a girl with brown eyes and short dark bluish hair. Because of her club activities as a basketball varsity player, she boasts an athletic physique, although she admits that her breasts might not be ample enough for Araragi to notice.
Her clothing style reflects her boyish personality; when she is not in the uniform of Naoetsu Private High School, she often wears sleeveless clothing and shorts. Whichever clothes she wears, she is regularly seen wearing cycling shorts, which she considers to be her underwear, much to Araragi's shock upon hearing it straight from her (as it implies that she does not wear panties).
Hidden from others, however, is her tendency to be jealous of others to the point of thinking of causing bodily harm to them for revenge. This would eventually fuel her killing intent as the Rainy Devil.
Back in elementary school, she inherited what she thought was a monkey's paw. At this time, she had been teased at for being slow in track. Because of this, Suruga decides to use the monkey's paw to grant her wish to become the fastest among her classmates. Unexpectedly, her competitors in one race she would participate in were attacked by an unknown assailant and were absent the next day. This would soon continue for some time, and this caused Suruga to be afraid, especially upon her discovery of the novel The Monkey's Paw, which tells the story of a similar item that grants wishes for a certain price.
Suruga would soon shift her focus to basketball, where she immediately shone as the school's ace player, and this caused Hitagi Senjougahara, the track ace at that time, to take notice of her talent. She and Hitagi become close friends,with Kanbaru calling their pairing the Valhalla Combo (ヴァルハラコンビ Varuhara Konbi, formed by the "varu" from Kanbaru and "hara" from Senjougahara), and she soon forgot about the monkey's paw. Immediately after she entered senior high school, she became aware of Hitagi's secret and was threatened by her, just like Koyomi was. However, unlike the persistent Araragi, Kanbaru followed Hitagi's advice and stopped talking to Hitagi since that time.
She then started stalking Koyomi after she discovered he was dating Hitagi.
In Suruga Devil, there seems to be a rumor about a devil solving other people's problem. Fearing that she might be the rumored "Devil," she decided to investigate and found out that the rumored Devil is actually an old basketball rival of hers named, Numachi Rouka. It seems that Kanbaru is still worried about the effects of the Rainy Devil after it has been dispersed to the point that whenever she goes to sleep, she would bind her devil's arm to a pillar so that she wouldn't start sleepwalking and committing crimes and check the newspaper everyday so that she can make sure she didn't do anything unconsciously. She also has dreams of her mother once in a while which give her weird life lessons.
She is named Kanbaru Suruga now but she was previously named Gaen Suruga. Izuko is her aunt and Suruga's mother had some kind of connection to oddities as she had inherited that devil's left arm from her mother. Her mother and father were revealed to have eloped as the Kanbaru family did not agree with their relationship. Kanbaru is also the only person that Kaiki will ever treat in a good way.