Itsuki Koizumi series caption first creator voiced name name nickname alias gender species nationality title relatives name name divider name name }} Itsuki Koizumi(古泉 一樹Koizumi Itsuki) is a fictional character from the Haruhi Suzumiya light novel series; in the anime he is voiced by Daisuke Ono in the original version, and Johnny Yong Bosch in the English dubbed edition. Itsuki is the last member to have joined the SOS Brigade, having been recruited by Haruhi as a "mysterious transfer student". Itsuki was sent to observe and keep Haruhi emotionally stable, in order to protect the rest of humanity. Although he is an esper, which is exactly one of the sorts of people Haruhi desires to meet, Itsuki never reveals himself as such, at least, not to her.