Tamaki is a ghost who died after suffering from severe neglect only a few years before the start of the plot. After his death, he passed briefly through Sherlock's morgue, before moving on to haunt the college dorms, and more recently Snake and Sora's room in particular, though he can be found around the building or even hanging around outside if they aren't home. It seems he mostly gravitates toward large groups of people, though only the supernatural and those humans who can see ghosts can see him.

When he gets lonely or agitated he tends to throw things around and make a big mess to try and get people to pay attention to him, so rumors that the dorm is haunted have probably spread even among normal students. He especially likes to knock things off shelves in the kitchen, since he's bitter that he always feels hungry but cannot eat. Other than throwing things, he cannot directly touch or hurt people.

Occasionally he is visited by psychopomps like Sans who try to get him to move on, but he very stubbornly does not want to. He would rather stay in this world, where there are plenty of other people, even if they can't all see him.

Maybe at some point Lambert will let him possess a pudding plushie and then he can travel around to more places, but for the start he is tied to the dorm.