TOMORROW X TOGETHER release their fourth Japanese single, CHIKAI. The single contains 3 songs, including two Japanese original songs and a Japanese version of "Deja Vu," ― the original Korean version is featured on their 6th mini album, minisode 3: TOMORROW. Limited Edition A (CD+QR card) comes in a DigiPack and includes a 20pg booklet, digital code card, photo frame, and a selfie photo card (Limited A ver.) (1 of 5 types / random).