Cut to the 1st floor roof, we can see Kiku and Kanjuurou in the ground. Momonosuke and Shinobu are running away. Kaidou is about to follow them but he’s stabbed in the leg by Kinemon, whose head is all bloodied.
Flashback to when Kinemon decided he has to act as Momonosuke’s father to conceal his true identity. We can see he had troubles saying Momonosuke’s name without adding "-sama" at the end (Raizou laughed at him). But they both practiced together until they can casually call each other "father" and "son".
Back to the present. Kaidou asks Kinemon what is the point of this struggling. He should just accept his defeat and die like a warrior. Kaidou then grabs a katana (it seems is Kiku's sword or the one that fake Oden used to stab Kiku) and stabs Kinemon, piercing his back and his abdomen.