One day, a magic button suddenly appears. The protagonists from KonoSuba, Overlord, Re: Zero − Starting Life in Another World, and Saga of Tanya the Evil all press the button occasionally, unintentionally and move to a parallel word another brand new isekai — where a new story featuring high school life begins. Soon, they are joined by protagonists from The Rising of the Shield Hero and Cautious Hero: The Hero Is Overpowered but Overly Cautious.

The film will feature the returning cast and staff from the anime's first two seasons. Minoru Ashina (Kaiju Girls, Pure Pure Purea Desu Overlord shorts) will write the script and direct the anime. Minoru Takehara will serve as both character designer and chief animation director. Studio Puyukai (Kaiju Girls, Lord Marksman and Vanadis, Pure Pure Purea Desu Overlord shorts) will animate the work.