Perfect World is TWICE's 3rd Japanese studio album, released July 28, 2021 via Warner Music Japan. It arrives in four versions: First Press Limited A (CD+DVD, 32-page lyrics booklet, 1 of 10 trading cards, serial number card), First Press Limited B (CD, 20-page lyrics booklet, sticker set, 1 of 10 trading cards, serial number card), Regular (CD, 20-page lyrics booklet, 1 of 10 trading cards on first press), and ONCE JAPAN fanclub edition (CD, 32-page lyrics booklet, 3×3 fold poster, 2 of 10 trading cards, 2 serial number cards). The 10-track album consolidates the three preceding Japanese singles — "Fanfare," "BETTER," and "Kura Kura" — alongside the pre-released title track "Perfect World" (MV dropped June 30) and six new album-only tracks including ballad "PROMISE," "Thank You, Family," and summer b-side "In the Summer." Jeongyeon was absent from the release showcase and the Music Station Summer Fes performance in August due to her ongoing health hiatus. The album was certified RIAJ Gold within its release month. A vinyl edition was also released and has been noted by collectors for its packaging quality.