Oreko is a small child wearing a diving helmet, a green dress, and no shoes. When interacted with in the underwater area, she gives Sabitsuki the Diving Helmet effect. Sometimes she is seen walking around in the underwater area and her house, and sometimes she is seen working on a large black and orange machine.
Oreko appears in two, possibly three other areas in the game depending on player interpretation. In the Industrial Maze she is seen floating in a tank, and this area leads to another area where, in the Sabitsuki chapter, she is seen holding hands with a bloody and beaten Sabitsuki, whereas during the endgame, she is missing and only the bloody and beaten girl remains.
However, during the endgame, another door is accessible in the north side of this area, which leads to a tank with a massive Sabitsuki floating in the same position as Oreko in the previous tank.
In the endgame, Oreko appears in the Alleyway Hospital, where her younger self can be found dead. She still remains floating in her test tube in the Industrial Maze. She can also be found in Dead Hole, but only in the endgame. She is nowhere to be found in the Underwater area.
- Her name is derived from the abbreviation of 'orenji' (Japanese for 'orange') and 'ko' (Japanese for 'child')
- If not otherwise occupied, she will follow the player around.
- A scientist who experimented on Sabitsuki and her illness. This explains friendliness, machinery and Sabitsuki-in-a-jar. The helmet can actually be measurement equipment disguised as a toy (it's not the same helmet as on Oreko herself which is used for preventing of disease transfer).