"I... I want you to stay by my side forever, and I want you to confess to me."

Kaguya Shinomiya is the titular protagonist of the Kaguya-sama wa Kokurasetai series. She was a student at Shuchi'in Academy, a member of the Archery Club, and the Vice President of the 67th and 68th Student Council.

Kaguya is a beautiful, fair-skinned young girl with long black hair that is usually tied by a black-red ribbon (her hair appears to be mid-back length when she lets it down) with bangs/hair strands hanging on either side, large, almond-shaped red eyes (that can look sharper, depending on her mood), thin eyebrows and a slim, but feminine build, with a noticeably small chest. She is described in her manga character profile as possessing 'stunning beauty'.

Kaguya was a very cold and rational individual, but she slowly changed after joining the student council. During her earlier days in council, she considered Miyuki Shirogane as one she would be fine to be in a relationship with if, and only if, he confesses first, thus she constantly plays mind games in trying to get him to confess. Later in the series, her actions imply that she is starting to accept her feelings of liking Miyuki, but won't openly admit it.

Due to being part of a wealthy and important family, Kaguya is sometimes seen arrogant and is very confident about her intelligence and incredible skills. However this is only an image she displays on the outside. Deep down she is always accompanied with an immense pressure for accomplishing her family's expectations, feeling desperate to do things her friends are able to do on a daily basis.

While she is a genuinely selfless and kind person at heart, given the unhealthy environment she grew up in, she doesn't consider herself a good person and as such, has a longing for true kindness that borders on obsession which she found in Miyuki. She cares about the members of the student council and considers them as treasured friends. Kaguya has a bad habit of immediately turning to money to solve her problems.