Is no one looking for Kaneki?
In episode 12 of the anime, it is explained in detail.


His dad died before he was old enough to form memories
His mom died from "overwork" trying to support Kaneki and her younger sister
His aunt (which took advantage of his mom) is obviously not the responsible type


As far as the anime goes, Kaneki does not have any other family. As a result, anyone that would care for him is dead, so they can't go looking for him, and his aunt doesn't care about him, so she would not look for him.