Enigma Boy, Part 4 (エニグマの少年 その④ Eniguma no Shōnen Sono 4), originally Smart Move! (賢い行い！ Kashikoi Okonai!) in the WSJ release, is the four hundred seventh chapter of the JoJo's Bizarre Adventure manga. It is also the one hundred forty-second chapter of Diamond Is Unbreakable.
Josuke bites his lip when he realizes he can't save Koichi. Crazy Diamond tries to punch Enigma but its fists fuse into paper, trapping Josuke within one. Yuya is relieved that he didn't help Josuke because he would have been next. However, Josuke uses Crazy Diamond to break a pole and then repair it, giving him some time before sinking into the paper.
Josuke says he knew the paper with Koichi's name on it must have been a decoy, but he tried to save the paper just in case there was a one in a million chance that it actually was Koichi. Before sinking due to Crazy Diamond not being strong enough to get Josuke out, he threatens Terunosuke that he'll kill him if he manages to escape from the paper.
Terunosuke is relieved that he succeeded, and tells Yuya that when he's afraid, he touches his chin. The smart thing for Yuya to do would be to stay neutral since he would be taken out easily by Enigma. Terunosuke then reveals a large piece of paper which a taxi containing a driver pops out of. The driver is confused as to how he got there, but Terunosuke asks him to drive to Morioh Grand Hotel.
To his surprise, Highway Star pops in through the car's door and takes Josuke's paper. Yuya was inspired by Josuke's speech and knows that he would have done the same thing if one of his fan-girls were in danger. Yuya is determined not to let people like Terunosuke and Kira roam Morioh freely.