In the present timespace, he is Haruka's classmate and the dhttp://en.wikipedia.org/wiki/Mitchel_Mussoeuteragonist of Noein: Mou Hitori no Kimi e. He, unlike other students, is being forced by his mother to go to cram school in order to pass a provincial enrollment test and go to a Tokyo junior high. As a result, he has little time for anything but studying. He initially tries to run away with disastrous results, and later has a blowup with his mother. Once the pressure is relieved, he realizes that he needs to take the exams because he has no special talents. (Source: myanimelist.net)
At the course of the story, it is revealed that he is Karasu, fifteen years to the future. He at first refuses to believe this, primarily because he thinks that Karasu is the reason why Haruka is in danger.
At the latter episodes, Noein reveals that he is Yuu, only with a different experience as Karasu.