(from amazon.jp):

It's Time To Create a new and invincible Judo!

The Shinsengumi, a group of jujutsu practitioners who plan to revive the old style of judo, stands in the way of Ryu Kazamaki, who trains in scientific judo! Will it work?

Harris Style Screw OTOSHI!

The year is 1961.

When Japanese judo faced an unprecedented crisis in the face of foreign judoka who used their physique as a weapon, a boy appeared who tried to create a new type of judo. His name is Harris-ryu Mudan--Kazemaki Ryu!

Ryu tries to protect the honor of Japanese Judo by studying "scientific Judo" together with Dr. Harris of Blaine. However, Kenosuke Yami, who uses the murderous Jigoku-nage (hell throw) technique, and the Jujutsu Shinsengumi, who plan to destroy judo and reestablish jujutsu, stand in his way.

The first secret technique of the Harris School, the Screw Otoshi, is the best way to counteract them!