can you identify this film?

[Frako Loden]

An acquaintance needs to identify the following film:

"I'm looking for a movie, Japanese, black and white, probably made in 
the 1960s.  A ronin falls in love with a woman (a prostitute?) and 
sells his sword to buy her contract.  Turns out the contract is owned 
by her husband: the ronin is swindled.   No money and no sword.   The 
husband gives the money to his father who uses it to raise an army of 
ronin. The swindled ronin winds up joining that army. Demons. 
Multiple camera angle work. Any ideas what this movie is?"

Frako Loden