Katze:
To play as Katze, the gunman, beat all 100 opponents in Slash Mode on the
Hard difficulty setting without continuing. It should say that you have made a
contract with Katze if you did it right.

Real Ending:
Do not touch anything on the control pad until you hear the character's
weapon click into place. Do not kill him from behind. Do not kill him on the
ground. Do not use your subweapon. The Bushido is hard to follow on the gun
guy.

The Second Ending:
First, you must have the first ending for the character you are using. You
cannot be TOUCHED through this whole process. Okay, run all the way to the
hole in the ground. Disable the other guy's legs and jump in. Go through the
game as you normally would and you should encounter a second boss after
Hanzaki. I think it depends on who your character is.

2 Player Battle:
You can do two player battle in normal story mode by pressing the start botton
on the second controller. You can play with your friends with access to the
every location in the castle. This means you and your friends can go anywhere
in side the castle and do battle at the same time.

Secret Characters:
Sorry if I miss inform anyone that there are no secrect characters after beating
Chambra mode from earlier post, But there really is one!!!! I just found out how
to select him in two player battle mode.
Here is how the get the Secrect Character: (He is only usable on TWO PLAYER
BATTLE MODE after you beat the Chambara mode) on player select screen, move one
spot left to Hotarubi or one spot right next to Kanuki. you will see nothing on
your character screen, the only weapon he can use is a hand gun. He is almost
invincible and he only has one stance.
You have to Beat the Chambara mode (I am not sure if you have to do it without
any continue or not, I did it without any continues by using the invincible
code) you might also have to get all the endings for all characters, I already
have them all, but I do'nt think you have to.