In Dead or Alive 1 Ultimate complete Arcade mode with ALL the characters and the settings on default to unlock Raidou.

Increase Bouncing:
Increase how 'bouncy' the girls are by going to the settings and entering your age as 99.

Unlock Hair Styles:
To alter hair styles press White or Black when selecting characters.

Change Arenas:
Press X or BLACK while selecting a stage to alter the arena.

Unlock Hitomi:
To unlock Hitomi, have a DOA 3 save on the Xbox and beat story mode on normal with Ein.

Unlock Tengu:
On any difficulty beat Story mode once with each character.

Unlock Bayman:
With Leon on Normal beat the Story mode to unlock Bayman.