Inside the Belly - S2.E5

The disguised Suzukawa attempts to bribe the 7th for Shiraishi's freedom, but he is killed Second Lt. Koito Otonoshi, who foils the plot on Tsurumi's behalf. Sugimoto flees with Asirpa, Ogata, and Shiraishi on an experimental hydrogen airship, though they are pursued by Koito. The group manages to throw Koito off the ship and escape the 7th by travelling through the Daisetsuzan mountains.