The Neverending Winter, the Land of Broken Dreams

Story

After winning tickets to an old theme park on the outskirts of Tokyo, Casio and his friends brave the eerie rumors surrounding the place for a little winter adventure. However, what was supposed to be a fun day trip takes a horrific turn when one friend lures Casio away from the group—and stabs him to death. While he bleeds out, his friend tearfully begs him to save someone named Asebi. When Casio next awakens, time has rewound to the moment he set foot in the park that morning.

Synopsis via AniList (English).