Like Yume Nikki and many of its fangames, there are a variety of events that Soutarou can come across in Mikan Muzou. This article contains a list of many of the events found throughout the game, along with their individual locations, their requirements to activate (such as sanity), and what consequences activating them may have.
Assembly Line Shenanigans
Location: Assembly Line.
Effect Needed: None.
Required Sanity: Any.
Description: From the starting point when entering from Black Stone World, go left, then down. If you try to go into the doorway on the right here, it will disappear without warning and you will hear laughter.
You can also go right twice, then down. In this room, there is a large hole if the mental state is below ten, and a round red creature with a single eye otherwise.
Arcade Chaser
Location: Old Arcade.
Effect Needed: None.
Required Sanity: Any.
Description: In the second room of the same arcade, a blond-haired chaser can be found playing on an arcade machine. Trying to hit him with the Knuckledusters — or to disturb him with several other effects — will result in him looking at Soutarou menacingly, revealing as well his hostile nature.
Behind the Doors
Location: Door World.
Effect Needed: None.
Required Sanity: Any.
Description:: In Door World, there is a dark blue door which disappears upon interaction and a green door that, when interacted with, will slightly open, revealing a big red eye behind it.
There is also a random chance that if you try to open any locked door, they will all open and show multiple red eyes.
Black Cat Flight
Location: Dirt Field.
Effect Needed: Black Cat.
Required Sanity: Low (>15).
Description: If it is night in the Dirt Field (indicated by being slightly darker than normal, and having a different background music; this usually changes every two dream sessions), go upwards and walk between four metal rods with a symmetrical grass pattern around them. Then go up and enter the building, go up all the stairs until you reach a big balcony. If it is night, there is a chance for a creature that looks like a hybrid of a bird and basket to appear here. By using the Black Cat Effect and interacting with the Bird Basket, you will start a flight cutscene with Soutarou in Black Cat form, sitting in the Bird Basket's basket while it flies through the night sky. Pressing the arrow keys controls the speed and direction of the moving background. When you start the event, the volume of the background music gradually gets louder until it is about twice as loud.
Black Stone World's Ghosts
Location: Black Stone World.
Effect Needed: Knuckledusters.
Required Sanity: Any.
Description:: If you equip the Knuckledusters effect in the Black Stone World, the ghosts wandering in the world will immediately disappear and you won't be able to hurt any of them.
Bloody Scenery
Location: Maid Mansion.
Effect Needed: None.
Required Sanity: Any.
Description: In the manor, there is a room with a moveable object that blocks a secret room. On the left side, there is a view of a river of blood. When exiting this room, Soutarou will look back at the scenery one more time before coming back to the manor.
However, if you have gotten your mental state as high as possible (29), walking up to the scenery will cause Soutarou to have a pained expression on his face and fall to his knees before waking up.
Bored
Location: Soutarou's Room.
Effect Needed: None.
Required Sanity: Any.
Description: In the real room, if you wait a little, Soutarou will yawn. Every time Soutarou yawns, his Mental State will randomly increase/decrease by 1 point.
Cave Chaser
Location: Dim Cave.
Effect Needed: None.
Required Sanity: Any.
Description: In the cave, there is a small hole in the wall at eye level. If Soutarou looks through it, he sees a calm chaser with blonde hair. If Soutarou looks through it again and the chaser is gone, he appears behind Soutarou and eats him offscreen, forcing Soutarou to wake up.
Cursed Room
Location: Migraine Hallways.
Effect Needed: None.
Required Sanity: Low.
Description: Entering the top left door, then the rightmost door. Walk to the top right corner and try to interact with the box there. Walking back toward the entrance will trigger the event; the floor starts to get darker, and the door will be locked, preventing you from exiting the room. Several arms then appear, chasing Soutarou. Touching one of them will force him to wake up.
After that, if you try to come back there, Soutarou will automatically refuse to do so.
Eye Box
Location: Sepia Island.
Effect Needed: Knuckledusters.
Required Sanity: Any.
Description: An event that works the same way as the Eye Box event from Yume Nikki. Find the box located east on Sepia Island, equip the Knuckledusters and interact with the object. Doing so has a chance to teleport you to a small room. Going into one of the doorways will only lead you to the other one, meaning that this room is a loop - you can verify it by using the Envelope effect. Interacting with the box again will bring you back to Sepia Island.
(Feigning) Ignorance
Location: Prison.
Effect Needed: None.
Required Sanity: Any.
Description: Find the large doorway in the gray building. Go upstairs, until you're on the third floor - the one after the floating gray teleporter. Attempting to go up again will result in Soutarou immediately going back out, with an uneasy expression on his face.
A similar event happens when you try to open the bloody dresser in the Rooms of Nothingness. The screen will fade to black, preventing you from seeing what's inside. Although this time, he'll act like there's nothing of note in there.
Glitching the Dream
Location: FC World.
Effect Needed: Distortion.
Required Sanity: Any.
Description: While in the FC World, equip the Distortion effect and press the action key. The screen will glitch, while a loud noise plays, before Soutarou wakes up.
Hazy Memory
Location: Soutarou's Dream Room.
Effect Needed: None.
Required Sanity: Any.
Description: Please note that you won't be able to witness this event if you have collected all effects.
In the dream room, keep waiting until you hear an alarm sound. Then, check the drawer next to you; a short cutscene will begin, showing with that appears to be some kind of fetus. The sound of a cardiometer can be heard in the background as well. Pressing any key will make Soutarou come back from the "trance" laying on the ground.
Viewing this event raises your Mental State by three.
The Little Girl in the Streets
Location: Abandoned Rooftop.
Effect Needed: None.
Required Sanity: Any.
Description: By going between the two lampposts in the Case effect's area, you'll find yourself in a backstreet where a blonde little girl can be found. Most of the time, she'll be wandering, although there is a chance to find her sitting. If you re-enter this area again, there are odds that Soutarou will find her unconscious, looking injured and possibly dead or dying. He'll head towards her and fall to his knees in despair before waking up.
Note that, when near this girl, Soutarou will refuse to equip any gruesome effects, like Centipede, Knuckledusters or Case.
Manor Shenanigans
Location: Maid Mansion.
Effect Needed: Knuckledusters/Frame.
Required Sanity: Any.
Description: Somewhere in the Rain Puddle World's sewers is a brown sliding door that is entrance to a manor, where dozens of housemaids will bow down before Soutarou every time he enters a hallway or a room, except when you have a certain effect equipped. If Soutarou wears the Knuckledusters before them, they will look down on him, before forcing him to unequip it.
In the room that's home to the Frame effect, using the latter will result in the original frame being fractured as well.
Nature of Chasers
Location: Various locations.
Effect Needed: Knuckledusters.
Required Sanity: Any.
Description: In this game, Shokushu as chasers work differently than in other fan games. If Soutarou attacks a calm Shokushu while wearing a bag on his head with the Knuckledusters effect, it will be killed. However, if Soutarou does the same action without the bag on his head, the chaser will become enraged. If Soutarou is caught while they are in this state, he will be transported to an inescapable area.
Railing NPC
Location: Cliffside Train Tracks.
Effect Needed: Frame.
Required Sanity: Any.
Description: When Soutarou uses the Frame effect near this NPC while you are in Foggy Bridge, it just disappears. However, if you use it in Cliffside Train Tracks this NPC lays in the water, seemingly dead.
Room of Bad Memories
Location: Migraine Hallways.
Effect Needed: None.
Required Sanity: Any.
Description: This is a random event with a 1/500% chance of triggering per second after seeing the Cursed Room event. Going back to the top left hallway, enter the second door and wait around in this empty room until Soutarou falls to his knees and sees a scene from his past. (This may only happen when you attempt to leave the room.)
Sewer Monster
Location: Toxic Sewers.
Effect Needed: None.
Required Sanity: Any.
Description: There is a black doorway in the sewers which leads to a room with a one-eyed green monster. If you go into the water to interact with it, Soutarou will be submerged by him as soon as he tries to leave, forcing him to wake up.
The Shapeshifter
Location: Inorganic Building.
Effect Needed: Knuckledusters.
Required Sanity: Any.
Description: Using the Knuckledusters effect on the chaser with the bag off Soutarou's head and allowing him to catch Soutarou will take him to an inescapable area with an NPC who shapeshifts in reaction to two effects. If you use the Pair of Hands effect, her head becomes a silhouette of hands, resembling elk horns. If you use the Black Cat effect, her head becomes a silhouette of a cat's head. She also can be killed.
Smiling Himemi
Location: Gray Wasteland.
Effect Needed: None.
Required Sanity: Any.
Description: Similar to the Poniko/Uboa Event from Yume Nikki. To trigger this event, enter the second-to-last house in the Gray Wasteland. It appears empty except for a big chair, which Soutarou can sit in. When you leave, a girl is briefly visible sitting in the chair. Repeatedly enter and leave the house (1 in 64 chance when entering) until the girl is visible while entering. From that point, the door locks and Soutarou can't leave her house. If Soutarou interacts with her, she will initially give him a cute smile, before turning into a creepy one, and then waking Soutarou up.
Unusual Chaser Traps
Location: Various locations.
Effect Needed: Knuckledusters.
Required Sanity: Any.
Description: There are several areas Soutarou can be trapped in by angering chasers which are not otherwise visible from the accessible parts of the world. These include Black Stone World, Serene Hill, and Colorful Settlement.
Being caught by any chaser in Red Hand Labyrinth takes you to the Nightmare Swirl.
The chaser in the Factory takes Soutarou to the top of a rock in Sepia Island. This rock is home to a small child NPC who bears a resemblance to child Soutarou. He will turn to look at Soutarou when interacted with, but otherwise has no reaction to any effects besides the Knuckledusters, which cause him to reach out towards Soutarou before dying.
From the entrance of the Assembly Line from Black Stone World; go up, up and left, use the Knuckledusters without the bag on Soutarou's head, hit the chaser and let him catch you. Soutarou will then be taken to the Monochrome Pixel Room; a strange white room with a clock, some furniture, and a door that is blocked off behind a counter.
Vending Machine Chaser
Location: Serene Hill.
Effect Needed: None.
Required Sanity: Low.
Description: This event requires you to have less than 100 yen. When you arrive at the end of Serene Hill, if a blond-haired chaser is there, interact with him. The chaser will go to the vending machine, buy one and give it to you. He will then wink at Soutarou.
Waking Up
Location: Various locations.
Effect Needed: Any/None.
Required Sanity: Any.
Description: Most of the effects have a unique waking up action. For example, if you have the Tape effect equipped, Soutarou looks like he is being taped until he disappears; if he's in the child state of the Down Jacket effect, he'll fall on his knees; or if he uses the Torso effect, he will disappear and leave behind a blood puddle.
What's also interesting is that the only time Soutarou will pinch his cheek like any other dreamer is when he has the Black Hair effect equipped.
Trying to wake up when he's already awake will result in him looking up - probably at the player - confused.
White Building
Location: Old Arcade.
Effect Needed: None.
Required Sanity: Any.
Description: In the arcade, interact with the machine that has a white screen to trigger a little cutscene, showing what seems to be either a church or a hospital. It won't do anything once it's over, but the next time Soutarou sleeps, another cutscene of that same building will show up, waking him up immediately. The arcade machine cutscene can be viewed multiple times, but the second cutscene is only viewable once.
White Cat
Location: Archaic Temple.
Effect Needed: Black Cat.
Required Sanity: Any.
Description: There is a white cat here, which can be in different places, determined randomly after Soutarou wakes up and falls asleep again. It can be sitting on a pedestal in first room, inaccessible between four holes in the third room, sleeping the basket in fourth room, or outside of the building, sitting near the vending machine. If Soutarou uses the Knuckledusters effect on the cat, it will run from him, but will return its position after exiting and re-entering the room it was in.