I Cannot Drown/guide

Higanbana
Go up in nexus to the higanbana field. Then go left until you find a Hone Onna (skeleton lady). Interact with the lady to get the effect.

Mask
Go up in nexus, follow the Higanbana instuctions and then go down until you find a pool of blood. Keep going right and get to the forest, then go down, left and down again. Interact with mask on the ground to get the effect.

Burning
Follow the instruction for the mask until you get to the forest. Keep going right until the second way up and then go right into the red light district. Go right past two Kappas (duck looking gals) and then go up. Interact with the Kitsune to get the effect.

Hunger
Go right in nexus to the road. Go down untill you find the restroom building. Go inside the male one and interact with the bloody urinal. Interact with the npc in the dark to get the effect.

Smile
Go right in the nexus to the road. Go down past the rail road until you reach the fence. Go left until you find a brush and ink bottle. Interact to get the effect.

Mermaid and the sea
Follow the mask directions to the forest. Go right instead of left and go down at the second turn. If you don't have the hunger effect equipped you'll see a girl that will run away from you. Go down and you'll see that she has turned into a mermaid. However if you have the hunger effect Ume will catch her and the screen will turn to red while loud eating noises are heard. After that her corpse will be seen here.

Sometimes the sea level will go down and the sea floor will be exposed, with a new entrance. Entering it brings you to a tunnel with corals and a pink haired npc. Interacting with it will teleport Ume back to her hole.