No Game No Life

Season 1

Episode 7: Sacrifice

While planning on challenging the Werebeasts, the siblings soon discover the difficulty in finding a strategy to defeat them; the memories of the Werebeasts' challengers regarding the games have all been erased. The siblings are at a loss, until Stephanie entrusts Sora a key left by the former king, unlocking her grandfather's secret research on how to outwit the Werebeasts.