The Ghost (ゆうれい) effect allows Sabitsuki to turn into a ghost. This in turn allows her to become invisible to NPCs by pressing the action key, useful for avoiding certain paths populated by active Kaibutsu. However it should be noted that the Ghost effect does not make Sabitsuki invulnerable and running into a Kaibutsu will still result in being transported to an inescapable area.
You can follow the Gas Mask Effect guide on how to get to the Plant Labyrinth. Once you enter where the nurse was, you'll be in it. From here, you need to take the door on the right. This is where it gets a little tricky. You go straight south, ignoring the first right turn. You keep going down till you can make another right turn. From there, you go slightly down till you can make yet another right turn. There should be a door. Once you enter, the next door should be to the right, very clear and straight path. And now you've entered the second Ghost Garden!
From the entrance, go north till you find what looks like a giant patch of white flowers. Be careful not to touch the middle one. This will bring you some place where you can't return! Go to the very top of the patch of white flowers, then go directly east till you hit one lone white ghost. From there, if you go north, you'll find the ghost effect!
- The Ghost effect is the equivalent of the Triangle Kerchief effect in Yume Nikki.
- It is a necessary effect to enter the Corrupted School.