Fans often discuss a recurring background character—a girl with a shell necklace—who appears in the flashback, sparking speculation about her identity as Tsukasa's sister. Quick Episode Summary Table Title "Stone World The Beginning" Key Event Senku's revival using the miracle fluid Flashback Senku's solo survival days and his struggle for fire New Resolve

We see Senku struggling to create fire and basic tools while being mockingly observed by a trio of monkeys. This montage is often cited by fans as both informative and charmingly funny.

Senku anticipated Tsukasa's move and ensured a small patch of petrification remained on his neck.