Kyon's Sister

Kyon's Sister is not given a name in canon, she is the younger sister of Kyon, the protagonist of The Melancholy of Haruhi Suzumiya. She refers to her brother using the 'kun' suffix, indicative of her being a forward type who treats their relations as equal. Normally this would be considered rude for a younger to say to an elder. She is also canonically the one to propagate the use of 'Kyon', said being a nick-name and her oniichan's real name never being revealed. She is most famous for her immortal phrase 'Kyon kun, denwa' during the Endless Eight arc.