Age
17
A friend of Kyon's from middle school. She first appears in volume nine. She introduces herself as a "close friend" of Kyon's, evoking feelings of jealousy in Haruhi. Many of Kyon's middle school friends, including Kunikida and Nakagawa, had developed the mistaken impression that Kyon and Sasaki were boyfriend and girlfriend, when they had simply become good friends due to attending the same cram and middle schools. It was this perceived relationship which led to Kyon getting the reputation of being interested in 'weird girls.' Sasaki is prone to odd philosophical musings and behavior which some might perceive as being atypical. For instance, she used the male 'boku' for 'I' when speaking with boys. Sasaki becomes a source of interest because her presence causes Haruhi to manifest Closed Space, and she has attracted the attention of a rival Agency similar to Koizumi's, who believe that Sasaki is capable of creating a distinctly different form of Closed Space. While Sasaki is, like Haruhi, pretty, intelligent, and eccentric, there are considerable differences between them. Sasaki displays none of Haruhi's boundless and sometimes random energy and seems to be somewhat dismissive of all emotion, considering it an inhibition to human development. Sasaki and Haruhi claim that emotions of love are like a mental illness. Haruhi, however, has admitted to sometimes feeling a desire to engage in a romantic relationship and is known to have dated a lot. Sasaki apparently has no desire to do so. However, she said that she was unable to keep from smiling around Kyon and there was a personal matter between them that she could not bring herself to talk with him about. Like Haruhi, Sasaki has been in contact with an alien, a time traveler, and an esper. Unlike Haruhi, Sasaki is somewhat aware of the backgrounds of her companions, although she feels that she does not understand the specifics as well as Kyon does.

The Melancholy of Haruhi Suzumiya
Kyon, your typical high school student, has long given up his belief in the supernatural. However, upon meeting Haruhi Suzumiya, he quickly finds out that it is the supernatural that she is interested in—aliens, time travelers, and espers among other things. When Haruhi laments about the lack of intriguing clubs around school, Kyon inspires Haruhi to form her own club. As a result, the SOS Brigade is formed, a club which specializes in all that is the supernatural. Much to his chagrin, Kyon, along with the silent bookworm, Yuki Nagato, the shy and timid Mikuru Asahina, and the perpetually smiling Itsuki Koizumi, are recruited as members. The story follows the crazy adventures that these four endure under their whimsical leader, Haruhi. The story is based on the light novels by Nagaru Tanigawa.