From Bakeneko Scanlations:
Tanaka Hajime and Harada were leaders of the yakuza group called Yanase. They were wiped out in the conflict between the Yanase group and the Kawa-guchi. The Kawaguchi group thinks that they killed Tanaka Hajime and buried him. Tanaka Hajime was saved by Harada, though he has lost all his memory. Knowing nothing, as Harada asks him if its a lie, Hajime states why would he. Then is when Harada tells Hajime that they are lovers. Is this true?