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). 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
Go to Colorball World and find a dress on the floor that gives you the Magical Girl effect.

Flashlight
Go to White Star World and go to the center of a cross that leads you to Black Star World, find a blue star NPC that leads you to the Neon Stairways and go up the stairway when you reached the place that has 2 stairways, interact with the NPC that leads you to Colorful Path, go to the down left corner 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
Go to White Star World and go to the center of a cross that leads you to Black Star World, find a blue star NPC that leads you to the Neon Stairways and go down the stairway when you reached the place that has 2 stairways, down to the Neon Street and go right to the apartment, go to the first room of second floor and interact with the dress that gives you Hakama effect.

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 Colorball World and find a clover that leads you to the Ocean, go to the end and interact with the 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
Go to Sepia World and find a mouse NPC that gives you the Sepia effect.

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, the Teddy Bear will appear beside her bed. [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. ]