As if it wasn't bad enough being haunted by the prospect of more overtime and looming deadlines, Tooru Seyama is working late alone (again) when an otherworldly presence makes itself known...

"What do you mean we couldn't get out from the Kotatsu!"
Four high school best friends in their early thirties gathered in the apartment for the first time in 10 years. The night is indeed perfect for some girl's talk under the warm kotatsu table. They were only talking about beautiful memories, but why suddenly they have to deal with this paranormal phenomenon?!