Amnesia/guide

Two Knots
Enter the Forest World. Follow the dirt path to the right of the door going upwards. At the end of the path there should be a blue-haired girl sitting on a bench (you may have to exit/re-enter the world if she's not there; it's also possible for her to be walking around nearby). Interacting with her gives you the effect

School Uniform
Go to Forest World, follow the path to the Two Knots effect, go north-west and find a locker. This brings you to the School. Leave the room you're in and go into the classroom below you. Interact with the NPC in the gray uniform.

Magical Girl
Enter the Colourball World. Go north-east and interact with a ribbon on the ground to get the effect.

Flashlight
Go to White Star World, go north-east to the center of a gray-black cross and step on the yellow tile, taking you to the Black Star World. Go south-west and interact with a blue star NPC to go to the Neon Stairway. Go all the way to the bottom and then take the ladder going upward on the far right. Go straight to the top and interact with the NPC. From where you enter the maze, go straight down and interact with the flashlight.

Cutter
Go to Colorball World and go into a blue ball entrance to the Blue Maze, go to the right part to find a hole to the Bottle World, go into a broken bottle and interact with the girl inside, go out of the bottle you will arrive to the Blood Path, go to the down left corner and interact with the Cutter.

Haunt
Go to Colorball World and go into a blue ball entrance to the Blue Maze, go to the right part to find a hole to the Bottle World, go into a broken bottle and interact with the girl inside, go out of the bottle you will arrive to the Blood Path, go to the down right corner and interact with a soul to the grave, interact with the ghost that gives you the Haunt effect.

Angel
Enter the White Star World, go north-east and step on yellow tile in the center of a large gray/black cross. This will take you to the Black Star World. Head straight up and interact with the halo with wings to get the effect.

Hakama
Enter the White Star World, go north-east and step on yellow tile in the center of a large gray/black cross. This will take you to the Black Star World. Go south-west and interact with a blue-star NPC to get to the Neon Stairway. Go down as far as you can. At the very bottom, where it splits off between two ladders, take the one going downward. Enter the building and go right until you reach a large gray building. Enter it and enter the room with the white light above it. Go into the room at the back and interact with the outfit on the floor.

Apple
Go to White Star World and go to the center of a cross that leads you to Black Star World, find a platform with 3 stars that leads you to the Hallway, go into an entrance that leads you to the FC Forest and go straight up until you reach an apple tree that gives you the Apple effect.

Teru Teru bozu
Follow the directions for the School Uniform effect. In the classroom with the NPC, interact with the desk in the top left corner with the vase of flowers on it. This'll bring you to the Apartments. Leave the tatami room and interact with the gray NPC to get transported to a maze. Navigate your way to the bottom right area of the maze. Interact with the Teru Teru Bozu to get the effect.

Drums
Go to Forest World and find a flower gate that leas you to the Rose World, find the Drums in that place.

Leaf
Go to Forest World and find a flower gate that leas you to the Rose World, find an entrance to the Village, enter the door that blocked by a NPC (use the Cutter effect) to the Autumn World and find the Leaf.

Cold / Flu
Go to Forest World and find a flower gate that leas you to the Rose World, find an entrance to the Village, enter the door that blocked by a NPC (use the Cutter effect) to the Autumn World and interact with a mouse that leads you to the FC World room, interact with the ice pack that gives you the Cold / Flu effect.

Sea Slug/Clione
Go to the Colourball World. Go north-east from where you find the Magical girl effect and interact with a clover on the ground. Go left and interact with the large grey stone. Turn back and interact with the tiny pink sea slug.

Cube
Go to Block World and enter a black building with an entrance, go to the end and interact with the Cube.

Sepia
Enter the Sepia World. Go down and left from the door and interact with a mouse-like NPC.

Endings
To achieve the first ending you need to find all effects, after that there will be a door appeared on the nexus' center to let you drop all the effects into the drawer. [But you can't drop the Cutter effect. Go into the door on the top will lead you to the ending. ]

[Toritsuki will get her cutter in her hand and goes into the room kill a shadow of Toritsuki, then she will back to life with the cutter in her room and doesn't want to go out of her room, interact with the Teddy Bear beside her bed will make her commit suicide by cutting herself. ]

To achieve the second ending you need to find the Teddy Bear in Teddy Bear World. This is found by going into Sepia World, heading south-west from the door and entering a blood-coloured gape. Go down the hall full of eyes and enter the Teddy Bear World. From there go up and left until you see two rows of teddy bears a tile apart from each other. Go between them and interact with the light-haired NPC. This will teleport you back to your room and the Teddy Bear will now be on your bedside table. [After you got the Teddy Bear, the effect dropping room will have a drawer appears on the top left corner, carry the Teddy Bear with you it will let you drop the Cutter effect, then go into the door on the top. ]

[Toritsuki will back to life in her room and can't go out to the balcony, interact with the door she will go out of her room and it will show there has a stair appears on the balcony. ]