Reaper Creeper (死神さん Shinigami-san, a reference to Kokkuri-san) is a divination game that allows interplanar contact in The World Ends with You. As a game mechanic, Neku can use his psychs to influence the game and give answers to RG people.
Reaper Creeper requires a sheet of paper, with three kanji, 白 White for "Yes", 黑 Black for "No", and a red outline of a torii shaped gate for "Neither". It is played with a coin, which is put in the center of the paper. If the RG person asks a question, the coin would slowly move across the paper. People believe that the "Reaper" is the one moving the coin, and that the Reaper always tells the truth and never lies.
Sanae Hanekoma writes about Reaper Creeper in his Secret Reports as a mode of popular communication between the UG and RG. The paralogos printed on paper allow limited UG interaction with RG objects. As RG people are unaware of Players, they perceive it as an illusion of a coin moving by itself.
Several times in The World Ends with You, Neku can influence the Reaper Creeper game played by RG people. The player drags the coin to one of the three symbols. However, if the coin is moved too fast, people will often doubt it and Neku will have to start over from the center of the paper. The coin must be dragged slowly for at least 3 seconds from start to finish to be successful.
It first appears in Week 1, Day 5. Neku and Shiki are introduced to it by Shrimp trying to get an answer in Tipsy Tose Hall, but forgets his question and asks the Reaper for it. They receive the Reaper Creeper meme from it. When they imprint it on two feuding girls, Ai and Mina, Ai gets the idea to play it with Mina to uncover the truth about Mina meeting with Ai's crush, Makoto Miki. While Shiki asks Neku to lead the coin to white lies to save their friendship, Mina tells the truth about how she was organising with Makoto to get a gift for Ai. Going to White for every question asked in this game between them gives Mr. Ducky, an item needed for the Secret Reports.
On Week 3, Day 3, Beat mistakes Reaper Sport 3 to be "Reaper Creeper" rather than "Tag", and leads Neku on a chase for Shrimp to convince him to play Reaper Creeper. They find him at Tipsy Tose Hall, being consulted by Makoto for advice about his business. While Beat wants to do the Reaper Sport, Neku believes he can't decide a dilemma like this through Reaper Creeper. If the Player does creep, Shrimp tries to convince Makoto to wear more clothes of whatever color the player went to, scaring him off. Choosing Black gives the Black Book Bag, an item needed for the Secret Reports. If the player refuses to play Reaper Creeper, Shrimp gives Makoto a pep talk and convince him to reopen Shadow Ramen. Shadow Ramen will then be open on Week 3, Day 6, Week 3, Day 7, Another Day, and A New Day.
- In the game, the item (B) Black Cat Atlas, Vol 10 tells the player that 'all you need is a coin, a sheet of paper, and a few crayons' in order to play. Playing Reaper Creeper requires Matoya's spell, "NEERC SEVAS EHT TARDNALD LOH" ("UNEMS DEE DEHTNO IKI HSSSERP" in Solo Remix and Final Remix). However, this is seen as a 'bit of a mouthful' and leads to most people not bothering. Given proper spacing and turned back to front, it reads "HOLD L AND R AT THE SAVE SCREEN" ("PRESS SHIKI ON THE DEEDS MENU" in Solo Remix). If this is done, the player can see their total time played.
- This is an allusion to the original Final Fantasy, where Matoya's broom gave the command to access the map backwards.
- Mina: White! Cool... the coin really moved! So, like... We said "if you're here, go to White." And it went to White. Whoa... that means... ...... The Reaper's here! Creepy! Can you believe it? Reapers really exist!
Ai: That's right. And they can see right through a lie.