Itsuki Koizumi

As the final addition to the SOS Brigade, this polite eleventh-grade student arrived as a mysterious transfer student recruited by Haruhi Suzumiya. Serving as Vice Commander, he maintains a cheerful demeanor and speaks with formal precision, often using animated gestures to deliver lengthy, speculative theories. He frequently shares these complex explanations exclusively with Kyon, with whom he enjoys playing various board games. Although he loses almost every match, his true intentions during these games remain a mystery to his companion.