TOMORROW X TOGETHER: Our Lost Summer follows SOOBIN, YEONJUN, BEOMGYU, TAEHYUN, and HUENINGKAI as they reunite after the pandemic and prepare for their first world tour, from Seoul to North America. As the pressure rises and nerves kick in, the group works through rehearsals and big-stage anticipation, aiming to deliver the performance of their lives at major stops including Lollapalooza.