Ep. 23: Senku and companions prepare tungsten and components for the first modified cell phone.
Aired on December 6, 2019

23
Senku prepares tungsten by crushing it into powder and heating it to extreme temperatures. He tasks Chrome and Kaseki with developing a precise high-temperature heating method based on their accumulated knowledge. Once the tungsten filament is ready, the group divides to complete specific assignments. Suika and her friends twist gold wire, while Senku and Chrome manufacture required plastic. Kinro, Ginro, and Kohaku burn coal to produce ash and construct a microphone. Meanwhile, Gen and Ruri build zinc-carbon batteries. After all members successfully finish their individual tasks, Senku assembles the components to create the first modified cell phone in the new world.
Episodes
- Ep. 19 · Hyoga's Fire Distraction and Senku's Cellular Phone Ambition
- Ep. 20 · Senku and Ishigami Village start cell phone construction, aiming for spring completion while developing gold filaments.
- Ep. 21 · Senku mechanizes iron production and develops light bulbs using tungsten for winter preparations.
- Ep. 22 · Senku, Chrome, and Magma search for tungsten and celebrate Senku's birthday with a village observatory.
- Ep. 23 · Senku and companions prepare tungsten and components for the first modified cell phone.
- Ep. 24 · Senku plays Byakuya's message and declares war on Tsukasa