No.9327814 ViewReplyOriginalReport
Itsuki is a male student in Kyon's year, although a different class. Although he not initially present in the story, he soon "mysteriously" transfers in from another school and is immediately recruited by Haruhi as a result. He is actually an ESPer and a member of the Organization, a secret group dedicated to their task of entering "closed space" and destroying the giant blue Avatars therein, which are created by Haruhi to express her stress and frustration. He is sent to the school to keep an eye on Haruhi and also to try and keep her entertained so that she creates less closed spaces and avatars, thus lessening the workload for the entire organization.

In the Brigade, Itsuki serves as Haruhi's right hand man, agreeing with all her plans and devising interesting things to do when she becomes bored. He also enjoys playing board games such as Go (despite being apparently very bad at them) and is prone to philosophical ramblings (usually in conversation with Kyon, much to Kyon's dismay).

Itsuki also appears to be ambiguously homosexual - although in the novels he is depicted as a smooth-talking gentleman, in the anime he seems distinctly more fabulous. It is generally accepted that he wants to molest Kyon, an idea which is the subject of a disturbingly large amount of fanart and has given rise to the phrase "(everyone is) Itsuki for Kyon".

Also, after the release of a 3D version of Hare Hare Yukai on a bonus disc that came with the new PS2 game, "Suzumiya Haruhi no Tomadoi", Itsuki was given the (nick)name "FABULOUS," due to the costume that he was wearing during the dance.