Mr. Osomatsu the Movie

After an awkward reunion with their accomplished former classmates, the Matsuno sextuplets find themselves grappling with feelings of inadequacy as they return to their lives as NEETs. In an attempt to drown their sorrows, they indulge in a night of heavy drinking, only to awaken in an unusual realm that brings their high school memories to life, focusing on one brother's deep-seated regret.

As they traverse this surreal landscape filled with echoes of their past, the brothers confront their younger selves and revisit the missteps that haunt them. Each encounter sheds light on the source of their entrapment, compelling them to uncover the identity of the brother whose regret has ensnared them in this chaotic world. With time slipping away and the fabric of their memories beginning to unravel, the sextuplets must act quickly to resolve their pasts and return to the present.