Bedroom Ghost

Muhyo and Roji's Bureau of Supernatural Investigation - Ep 21 (Under the Sod): Muhyo and Roji return back to their old building (having lost it to Goryo in a wager) where they run into their friends, Nana and Kenj. After finding it abandoned for some odd reason, they settle in to rest for a bit. While talking Kenji mentions feeling an odd presence while playing his recorder earlier. Roji, Nana and he investigate the room he felt it and it seems normal... at first.

Example of:
Stringy-Haired Ghost Girl