Akanesasu Shoujo

Asuka Tsuchimiya and her friends in the Crystal Radio Research Club try a local urban legend: play a certain frequency before the sacred Akeyuki Tree at exactly 4:44. They expect nothing to happen, but the ritual carries them into a parallel world resembling their own with unsettling differences, where Asuka meets a far more serious, battle-hardened version of herself.

The girls learn that each world is a "fragment" formed from different possibilities and that a force called Twilight is consuming those possibilities one by one. Traveling between fragments lets them see lives they might have lived and exposes fears and desires they ignored. Protecting the worlds requires understanding themselves as much as fighting the enemy erasing their futures.