The third single in Japan! Their second full-length album "THE WORLD EP.FIN : WILL" reached No. 1 on the "Billboard 200," and they are now globally popular. The title song "NOT OKAY" was newly written for this Japanese original single. The limited edition type B comes housed in a slipcase. Includes a 36-page photo book and a selfie trading card (B) randomly selected from 16 kinds.