8-Gatsu 31-Nichi No Long SummerThe Long Summer on August 31; 8月31日のロングサマー; August 31st Long Summer; Hachigatsu Sanjuuichinichi no Long Summer; Mùa hè dài ngày 31 tháng 8; 8-gatsu 31-nichi no Long Summer

Suzuki-kun and Takagi-san are two high school students who met in a time looping August 31st. Only the two of them keep their memories. The cause of the time loop is believed to be something Suzuki-kun has left undone over summer vacation, a teenage boy's biggest goal...A youthful time loop comedy that faces romance head-on!---- (https://morning.kodansha.co.jp/c/831longsummer.html)