Thieves broke into Yamashiroya, a drug wholesaler, and stole 780 ryo. In the storehouse, there was a sticker with a picture of an umbrella, the signature of Yahei Kasayama, a great thief who once ransacked the entire Kanto region. Heizo Hasegawa (Kichiemon Nakamura), the director of the reform of the thieves, learns that the theft was the work of Yahei's son Yataro (Somegoro Ichikawa [now Koshiro Matsumoto]) and his gang, thanks to the help of a spy named Isaji (Koichi Miura).