Magpie Dreams/guide

Broomstick
In the nexus, enter the cityscape door and go up the path. After that choose the left path and go on it for a while. Upon returning you will be transported to another section of the road and behind one lamp post you will find a winged broom. Interact with it and you will receive the Broomstick effect.

Umbrella
In the nexus, enter the blue door and go northwest until you reach a small arch. Go through it and you will arrive to some underwater temple ruins. Inside the temple, keep going up and interact with the umbrella from the room with the jellyfish. You will receive the Umbrella effect.

Hair Dye
In the nexus, enter the pink door and go southeast until you reach a blue cross-shaped pattern on the ground. You will be teleported in a dark world with coloured mosaic tiles. Go to top right → bottom left → middle left shapes and you will reach an area with a girl with long hair. Interact with her and you will receive the Hair Dye effect.

Piano
In the nexus, enter the cityscape door and go up the path. After that choose the right path and enter the building. Take the subway and when you arrive at your destination walk around the city until you find a dark NPC with horns and a white face. Interact with it and you will be teleported to a theatre. Go upstairs and pick the left corridor. Go to the bottom of the left corridor and enter the room. Listen to the man sing the entire song and at the end some stairs will appear so you can go up the stage. Interact with the man on stage and you will be granted the Piano effect.

Inverse
In the nexus, enter the pink door and go northwest until you see six aligned trees. Go through the path in the middle and advance the tunnel until you reach the area with a castle. Enter the castle, go upstairs and interact with the big mirror. You will receive the Inverse effect.