Chiaki Mukai (迎 千秋 Mukai Chiaki) is the captain of the Penguin Manju Go. He is assumed command of the vessel at Gin Tōdō's request. He previously captained an Antarctic observation team while a member of the SDF.
As Captain, Mukai is presumed to have taken only the main characters back to Australia at the conclusion of their journey.
- The name Chiaki means "thousand" (千) (chi) and "autumn" (秋) (aki).
- Chiaki's surname Mukai means "welcome" (迎).