He returns in The Dissociation of Haruhi Suzumiya, allied with Kuyoh Suoh and Kyoko Tachibana in an effort to transfer Haruhi's power to Sasaki. In The Surprise of Haruhi Suzumiya it is revealed that he is Mikuru's brother, and that his goal is to restore the original timeline in which Mikuru exists.
In "The Dissociation of Haruhi Suzumiya," he joins forces with Kuyoh Suoh and Kyoko Tachibana to transfer Haruhi's powers to Sasaki. Later, it is revealed that he is Mikuru's brother, aiming to restore the original timeline where she exists.