Itsuki (樹), also known as Gatekeeper (闇撫の樹), is a demon who can traverse dimensions and one of Sensui's comrades. Having been with Sensui the longest he has grown very fond of him, stating that he wishes for Sensui to be his lover. Itsuki controls a being known as the Reverse Man, a shadow living between dimensions. Itsuki is voiced by Kōji Tsujitani in the Japanese version and by Jerome Fifty-Seven in the English dub. Itsuki one of author Togashi's favorite characters; he stated after the series ended that he wishes he had been able to expand on the character's twisted psyche.He also noted the portion of the plot where Itsuki speaks inside the Reverse Man to be his favorite of the series because it reflects how the mangaka was feeling at the time.