Go to free mode, then select Kunoichi as your character. At the "Pick A Scenario" screen,
select Yukimura's Tale. Then, select the first stage. When you start the level, another
Kunoichi will appear behind you. The one that appears behind you is Yukimura's officer.

Successfully complete one two character's campaigns to unlock Masamune.

Successfully complete Mitsuhide Akechi's campaign to unlock Ranmaru Mori.

Successfully complete Okuni's campaign to unlock Goemon.