As of Version 2.0, those who had 100% completion in the original game will now show these new statistics for their save files:

• Effects: 71%
  
• Collectibles: 93%
  
• Dreams: 85%

Only one new item was added from this update. The rest of the collectibles are Concept Art and one jellyfish.

There's a lot to collect in Yumenikki -Dream Diary- to get that Lucid Dreams achievement, but it should comfort you to know that most of these items are required to access certain parts of the game. But there are also a few items that are easy to miss as well, which is why this guide exists. If you have collected all 44 pages 50 pages of the Dream Diary but you're still missing some collectibles, then you might be missing some of the quest items.

This guide contains detailed instructions and screenshots on where and how to get the items. So naturally, this guide is full of SPOILERS.

For the purpose of recognition, I will refer to most NPCs by their fan-given names on the Yume Nikki wikia[yumenikki.wikia.com]. Because of the semi-nonlinear nature of the game, the items will be listed in alphabetical order.

Please feel free to make suggestions to this guide. If something isn't clear enough, please speak up.

For the locations of the Jellyfish, check this: https://steamproxy.net/sharedfiles/filedetails/?id=1311110216

For the locations of the Concept Art, check this: https://steamproxy.net/sharedfiles/filedetails/?id=1313567179

Location: Pier. There are ten pieces scattered in this area. You need them all to use the vending machine. Note: there is an item worth 120 yen in the vending machine, but it is currently impossible to get that much money in a normal playthrough. The item may be just for decoration.

Location: Pier. Collect all ten yen pieces scattered across the pier. Then look for a vending machine and purchase the 100 yen item, which turns out to be a Blood Bag. Give it to the Fisherman at the beginning of the area.

Location: School, 1st floor. You need the Stack of Books first. Trade it with the Pirori in the classroom to get the Brush.

Location: Desert (same area as the glyphs puzzle). To the southwest, there is a face cube with the glyph inside its eye.

Location: The Dark Forest area past the Pier. You need the Hamsa effect to get this item. At the pier, you must fulfill the requirements to move the Strober NPC out of the way. Proceed east and move past the lighthouse section. Eventually, you will come across a dark forest full of Nopperabou Witches. Towards the end, you will find a single Kimajo (tree with a face). Use the Hamsa effect to reveal a hidden door, which will take you to a mansion containing the game cartridge. The game itself is an homage to Ao Oni, a survival horror RPG Maker game. To play it, you must use the Famicom in Madotsuki's room while you're dreaming.

Location: Madotsuki's room. Play Super NASU on the Famicom once.

Location: Take the Train at the Desert Settlement. You need the Flute effect to get this item. Speak to the one-eyed Train Passenger and he will play you a song. Repeat this song on the flute and he will give you the Kalimba. You can give the Kalimba to a house-dwelling Pirori at the Desert Settlement, who will play you a song. Note: this item can be easy to miss if you guessed the correct song to play to the Mural world creature, who will give you the Moon Glyph.

Location: Mural world. At any location with the train, enter and exit until you arrive at the Mural world. To the east of the map, the Kite is stuck in one of the trees. This item is required to get one of the glyphs.

Location: Ruined School, 1st floor. Enter the rightmost classroom and it should be nearby. Same area as where you find the Toilet Key.

Location: Mural World. You need the Flute effect to get this item. I recommend you get the Kalimba item as well. Go to the Desert Settlement and enter a house towards the center of town. Inside, there is a Pirori. Give him the Kalimba and he will teach you a song. Then, take the train to the Mural World and find an odd creature surrounded by murals. Play him the song and he will spit out the Moon Glyph.

Location: Mall Rooftop (added as of version 2.0). In the left section of the Sewer, there is a Black Cat. If you approach it, it will vanish into a pipe. Go to the nearest ladder, which will take you to the Mall. Go to the Mall Rooftop and you will meet the Black Cat there. It will give you the game, which you can play on your Famicom while in the Dream World.

Location: School. When you first enter inside the building, it should be visible from a school locker.

Location: School, 2nd floor. You need the Triangle first. Give it to the Fleebie/Follony (one-eyed ghost) in the classroom to get the photo fragment.

Location: School, 3rd floor. Inside one of the classrooms. Same area as Monoe's Concept Art.

Location: School, 2nd floor. On the 3rd floor, there is a short set of lockers you can push. Push it down the hallway towards the staircase for the 2nd floor. Push it down the hallway more and search for a white sparkle somewhere close to the ceiling.

Location: Desert (same area as the glyphs puzzle). You need the Knife effect to get this item. To the east of the map, there should be a Batsu (red-eyed plant). Attack it to get the Red Eye.

Location: Mall. This is possibly the trickiest quest item to find in the game. To obtain it, you need both the Umbrella effect and the Lantern effect. Then, bypass the mannequin hallways (this is significantly easier with the effects you have). When you enter the room full of cardboard boxes, use the Umbrella to double-jump to the top left area. There is a hidden door containing a dark room full of mannequins. Use the Lantern effect and move left to avoid getting killed. Eventually, you will find something sparkling in the darkness. To use the key, you must return to the beginning area of the Mall and enter the first room you see. Take the elevator and you will find a locked door that requires the Rooftop Key.

Location: Final Area, 2nd floor. There is only one unlocked door in the hallway. Enter it and you will eventually find a dimly lit room with a single desk. The desk has the key to leave the building.

Location: Pier. You need to purchase the Blood Bag and give it to the Fisherman NPC at the beginning of the area. He will give you the Sad Fish in exchange. Give the Sad Fish to the Strober NPC to move him out of the way, allowing you to access a new area.

Location: School, 2nd floor. It should be sitting on a shelf somewhere in the hallway. Give this item to the Pirori on the 1st floor.

Location: Desert Settlement. First, you need to trap the Mouth Monster in the cage at the center of town and get the Kite item. After you trap the monster, the Pirori will come out of the houses. At the northeast side of town, there will be a Pirori sitting on a crate. Give him a Kite and he will trade you the Sun Glyph.

Location: Ruined School, 1st floor. Enter inside the rightmost classroom. Then, use the Hamsa effect to reveal a hidden item on a desk. Same area as where you find the Lever. To use the key, return to the 3rd floor of the original school area and search for a locked restroom.

Location: School, 3rd floor. You need the Brush first. In one of the classrooms, speak to the Walking Eye NPC and trade him the Brush to get the Triangle.

Location: Mall. Enter the room at the beginning of the map and take the elevator. The valve should be on one of the shelves. This item is required to finish the School area.

Location: Desert Settlement. First, you need the Red Eye and the Wood Plank. Go to the cage at the center of town and set up the trap with the two items. You must lure the Mouth Monster into the cage. To avoid getting caught by the monster, climb onto the crates. When he seems to have given up chasing you, wait until he's a few paces away, then move towards the next crate. Repeat the process until you trap the monster in the cage. Then, the Pirori NPCs will come out of the houses. To the southeast side of town, one of the houses will be open, containing the War Glyph.

Location: Mall. In the first area, Tokuto-kun will flee with this item. You must corner him to get the key and progress to the next area. My recommended strategy is to change the direction of the escalators using the levers to lead Tokuto-kun to the 1st floor. An escalator with a blue light means it's moving upwards, while one with a red light is moving downwards. For the escalators between the 1st and 2nd floors, make sure most of them are moving downwards so that Tokuto-kun can't use them. Eventually, you will lead him to a dead end and he will tilt over, granting you the key.

Location: Pier. Go to the screen with the train and the Strober NPC. To the left, you should be able to pull off the Wood Plank. You can also get the Hamsa effect further down.

Location: Seccom Masada-sensei's spaceship. To enter this area, you must fulfill the requirements to unlock the secret ending. You must have already found all five hidden Jellyfish in each world. In the Final Area, first floor, check one of the rooms for a red symbol on the wall (resembles three female symbols). Interact with it and go to the stormy rooftop. Go to the left from the entrance and you will find this symbol on the ground. Interact with it and you will be transported into Masada-sensei's spaceship. Check the table for the item called ???. This item will also register as the final Concept Art for the Dream Diary.