Yuki Nagato (長門 有希, Nagato Yuki) is a fictional character in the Haruhi Suzumiya franchise. She is initially portrayed as an introverted, taciturn bibliophile. She is actually an artificial human created by the Data Overmind (情報統合思念体, Jōhō Tōgō Shinen-tai, translated as Data Overmind in the novels, but as Data Integration Thought Entity in the anime), and possesses supernatural powers as a result. She did not act to join Haruhi Suzumiya's SOS Brigade, instead coming with the room that Haruhi appropriated, and then being listed on the forms Kyon filed to establish the club. She observes and takes part in club activities on the behalf of the Entity while still being the only member of the Literary Club. In addition, she is present to ensure that Haruhi does not use her godlike powers, and aids the other Brigade members in stopping forces that cause her to do so. The alternate Yuki established in the fourth light novel, The Disappearance of Haruhi Suzumiya, is the main character of the spin-off manga The Disappearance of Nagato Yuki-chan.