Directed by Mansaku Itami.

Jewel thieves become interested in an invisibility formula invented by Professor Nakazato and want to use his invention to acquire a diamond necklace called the "Tears of Amour."

Date Mosui, a young samurai, one day gets a scolding from a nameless ronin that sets him thinking about what life is all about and his ways of living. His frined, Ando Kichinosuke, is alarmed at Mosui's despondency and invites him to his house as his little sister Tsuyu and he try to cheer him up.

A samurai is ordered by his lord to go to Edo and investigate the truth behind the rumor of a rebellion against him.

In the midst of the depression, two ronin rack their brains to come up with a dishonest scheme. Taking a man from the countryside, they fashion him into Ise Isenokami, the finest swordsman under the sun. Pretending to be his followers, they visit various sword fighting dojo. Out of fear upon hearing the name Isenokami, they pay him off and do not let him enter their training halls. The impostor eventually comes face to face with the real Isenokami after rescuing his daughter, Oyae, who is caught up in a minor incident.