Following a mortifying high‑school reunion where their peers flaunt successful careers, relationships, and families, the Matsuno sextuplets return home to brood over their NEET status. They spend the night drowning in alcohol, eventually passing out, only to awaken inside a bizarre realm of memories focused on one brother"s biggest high‑school regret.
While traversing this memory landscape, the sextuplets meet their awkward former selves and those of friends. Throughout, they seek to identify which regret has bound them here so they can escape back to the real world. Yet time is slipping away; the memory realm is volatile, and if they move too slowly, they risk losing the chance to set things right.
