Yume-san/guide

Ninja
Enter the orange door. Go down to the next section and interact with the large orange creature. Enter the door with the shuriken on it. Go right and down, you'll see silhouettes of dogs moving forward several paths. Go through the third path (the one with the darker ground.

Go right and you'll now be in a maze. Work your way to the bottom-left corner of the maze and find/interact with the headband.

Ghost
Enter the blue door. Choose: [Right, Left, Left, Left, Right]. Interact with the ghost NPC.

(While here, get Yume's Legs)

Microphone
Enter the orange door. Go down to the bottom section, go right and go between the red trees. Go north-east and interact with the microphone on the wooden stage.

(While here, get Plushie)

Colour
Enter the red door. Go north-west to a group of bushes. Go under the small red cloud. Go south-east and enter the hollow cuboid. Go all the way to the right and interact with the sparkling NPC.

Fluffy
Enter the red door. Go north-west to a group of bushes. Go under the small red cloud. Go south-east and find two NPC's beside a floating red circle. Interact with the circle to get the effect.

Chalk
Ghost, Seal, or Witch effect is needed to get this effect

Enter the night door. Among the neon green "plants", there will be a different one. Interact with it to be transported to a new area. There you will find a short water channel. Interact with it from the bottom side. You will be taken to a small field area, where you can see a door in the middle of a lake. The door is accessible from the bottom area of the lake if you have the ghost, seal, or the witch effect. Enter the door, and you will be in a small area with two NPCs. Interact with the pink-haired NPC, and she will transport you to a monochrome area. Once you're there, go down until you find an igloo village, and then turn to the left and walk until you find a single igloo surrounded by white NPCs. Enter the igloo to find the effect.

Seal
Ghost or Witch effect is needed to get this effect

Enter the night door. Among the neon green "plants", there will be a different one. Interact with it to be transported to a new area. There you will find a short water channel. Interact with it from the bottom side. You will be transported to a small field area, where you can see a door in the middle of a lake. The door is accessible from the bottom area of the lake if you have the ghost or the witch effect. Enter the door, and you will be in a small area with two NPCs. Interact with the NPC on the left.

(While here, get Chalk, Candles and Yume's Paws)

Plushie
Fluffy effect is needed to get this effect

Enter the orange door. Go down until the last section and go between the red trees, taking you to a forested area. Go down and right until you find a yellow yarn ball and interact with it. In the yarn world, cross the purple yarn-patterned door, taking you to another area. There, find a little yellow cat. Equip the fluffy effect and interact with the cat to be transported to a corridor. Go until the end of the corridor to find the effect.

Witch
Enter the red door. Go north until you reach the screen door. Go right to the 9 red cats. Interact with the bottom cat, the one with the different tail.

Coal
Microphone effect is needed to get this effect

Enter the night door. With the microphone effect, interact with all four very spiky green NPCs. A black-haired NPC will appear somewhere in the map, interact with them to be taken to another area. Travel north and enter the dark house. Interact with the item on the floor.

Candles
Ghost, Seal, or Witch effect is needed to get this item

Enter the night door. Among the neon green "plants", there will be a different one. Interact with it to be transported to a new area. There you will find a short water channel. Interact with it from the bottom side. You will be transported to a small field area, where you can see a door in the middle of a lake. The door is accessible from the bottom area of the lake if you have the ghost, seal, or the witch effect. Enter the door, and you will be in a small area with two NPCs. Interact with the NPC on the left, and you will be transported. Equip the microphone effect and interact with all the bubbles above white spots.

(While here, get Yume's Paws)

Yume's Head
Enter the red door. Go north and enter the screen door. Enter the far-left door and interact with the moving head. Go East and interact with the head.

Yume's Body
Enter the red door. Go south and enter the door. Enter doors until reaching an area with lava. Talk to the NPC.

Return to the nexus and enter the night door. Go south-east and interact with the different green neon object. Go south-west and interact with the moving black spot. Interact with the object that appears to the right.

Yume's Paws
Ghost, Seal, or Witch effect is needed to get this part

Enter the night door. Among the neon green "plants", there will be a different one. Interact with it to be transported to a new area. There you will find a short water channel. Interact with it from the bottom side. You will be transported to a small field area, where you can see a door in the middle of a lake. The door is accessible from the bottom area of the lake if you have the ghost, seal, or the witch effect. Enter the door, and you will be in a small area with two NPCs. Interact with the NPC on the left, and you will be transported. Go north-west until you reach bubbles with candles inside them. Walk up to the NPC and equip the seal effect. Interact with the NPC, then interact with the object that appears.

(While here, get Candles)

Yume's Legs
Enter the blue door. Choose: [Right, Left, Left, Left, Right]. Go through the door on your right. Go south-east and interact with the fish. Go down and right, interact with the tiled door. Go right, then follow the path straight up. Interact with the legs on the ground.

Ending
Collect every effect and plushie part, then interact with the sewing machine on the balcony.