Histoire de Yakuza.

Yaoi.
Yakuza as a plot.
There's no words to describe how amazing this story is. It's Yoneda Kou's work after all.

Yaoi.
Some of the stories has yakuza as a plot/background.

Yaoi / One shot.
Yakuza as a subplot.
Connected to Saezuru tori wa habatakanai.

Yaoi / Action / their forcefull relationship might not be to everyone's taste.
Yakuza as plot.

Yaoi / Action.

Yaoi.
Yakuza as plot.
Great art, great story.

Yaoi.
Yakuza as a background.

Yaoi.
Yakuza as background.

Yaoi.
Yakuza x doctor.
Yakuza as part of the plot.

Yaoi / Fantasy: Kami-sama x master. / Multiple stories.
Sole of the stories as Yakuza as a background.