Itsuki Koizumi is a fictional character from the Haruhi Suzumiya light novel series. He is the fifth person to join the SOS Brigade, recruited by Haruhi Suzumiya because he fit with her idea of a "mysterious transfer student", after he was transfered into North High. This character is popular among cosplayers. It can be portrayed by wearing cosplay Itsuki Koizumi costume and cosplay Itsuki Koizumi wig. This character is always present in a Haruhi Suzumiya cosplay.