|Spoiler warning: Plot or ending details follow.|
Go to the Creature World, go south-east and interact with the purple floating creature.
Go to the School, go to the left path then go to the bottom pathway to School II, go through the way to the west part, interact with the magnifying glass.
Go to the Gate World, go up one row and interact the little cat.
Paper Knife Edit
Go to the White Paper World, go north-west and interact with the paper knife.
Go to the Branch World, go south and interact with the bell surrounded by branches.
Go to the Forest World, go straight left until you reach the tricycle.
Go to the Japanese World, go south-west and interact with the Wafuku in front of a stage.
Go to the Ink World, go south-east until you reach a pattern floor then go south, interact with the NPC.
(It's better to have Light effect)
Go to the Dark World, go north-west and interact with the bat on the tree.
Go to the Light World, go left one row and interact with the light orb that keeps going south.
Go to the Forest World, go north-west and find a stair to the Pearl Curtains Pathway, go to the end and interact the blue Hell Block to the Bookcase Hell, go straight left then go up before reach the end, go left and interact with the stick to the isolated place, enter the door to the Magic World A, go north-east and go between the sticks with white diamonds to the Reverse Pathway then go right to the Magic World B (the diamonds on the sticks will change to black color), go south-west and interact with the NPC.
Go to the Ice World, go west until you reach the big ices then go north, interact with the small ice.
Go to the Mirror World, go south-west and interact with the glass statue.
To get this effect, you must sleep at least 14 times. Go to the Bookcase Hell's south-east part, find the entrance to the Secret Place, go through the way to a room with bookcases, interact with the butterfly.