Janken Boy Is Coming!, Part 2 (ジャンケン小僧がやって来る！ その② Janken Kozō ga Yatte Kuru! Sono 2), originally Rock-Paper Rock!! (ジャ～ンケン グー!! Ja～nken gū!!) in the WSJ release, is the one hundred seventh chapter of Diamond is Unbreakable and the three hundred seventy-second chapter of the JoJo's Bizarre Adventure manga.
A strange boy insists on challenging Rohan to a game of rock paper scissors. Rohan suspects that he is a Stand user and transforms him into a book with Heaven's Door. He learns the boy's name: Ken Oyanagi, but sees that he is an ordinary child obsessed with rock paper scissors. He then accepts to play, and wins, taking the taxi for himself.
Later that afternoon, Rohan stops at a café in order to sketch for his next chapter, and stumbles upon Josuke, Okuyasu and Yukako. They invite him to their table, but Rohan doesn't want to talk to them. Ken Oyanagi appears and takes the last empty table, infuriating Rohan. Ken begins to make a scene when Rohan orders him to leave, which makes everyone look at the mangaka. He challenges Ken to another game and wins again. Rohan then happily kicks the boy out of the table.
At a library, Rohan is eyeing an illustrated compendium on plants, and plans to buy it. But Ken appears again and takes the book for himself. He challenges Rohan to another game, but this time, Rohan punches Ken at the count of scissors. Rohan orders the kid to stop but Ken claims that he's won the game, having thrown paper. Rohan realizes that Heaven's Door is being sucked out into the hole on Ken's cheek.