It is explained how Genzo had turned into a dove, in that he also had previously entered the chamber. Seikichi is upset that Sora stayed out all night with Ginjiro, afraid she might be found out. Tetsuju chases Genzo into the row house, using a self-propelled fire boat, catching the eyes of the residents. It is revealed that Tenho and Tenten are lurking inside Ginjiro's room. Akai spies on Ginjiro, who takes Tenho and Tenten with him to see Toyama. Ginjiro tells Toyama that he is working for Torii at his own will, not due by force. Meanwhile, as Seikichi tests out his own fire boat, a selfish Tetsuju challenges him to a race. When an angry Oriku soon joins them, she blows up the fire boat, causing Seikichi to drown. Sora then reluctantly dives in to save him.
試し打ちを繰り返す清吉たち。その都度、作り上げたからくりが壊れることに、六兵衛や新座もさすがに少々閉口していた。そこへ連れ立って朝帰りした銀次郎とソラ。その姿を見た清吉は、素直にソラと接することが出来なかった。そんな中、風来長屋に鉄十が運んできた船の仕組みを見た清吉は、ある工夫を思い付き…。
