Helena, Spartan, Leon, Gen Fu and Tengu. For unlocking Tengu you have to unlock all hidden characters and beat time attack mode with everyone. (Takes around 17 hours to do if you are really good.)
Alternate character appearance
At the character selection screen, press A to select a character, then press X, Y, or Start. Press A to start the match with the alternate appearance. Not all characters have an alternate version.
Complete Story mode to unlock an alternate costume with the following characters. If available, the next alternate costume for that character will be unlocked when Story mode is completed with them again.
Ayane C3, C4, C5, C6
Bass C3, C4
Brad Wong C3
Christie C3, C4
Elliot C3, C4
Hayabusa C3, C4
Hayate C3, C4
Helena C3, C4 C5
Hitomi C3, C4, C5, C6, C7, C8
Jann Lee C3, C4
Kasumi C3, C4, C5, C6, C7
Kokoro C3, C4, C5, C6, C7
La Mariposa C3, C4, C5
Leifang C3, C4, C5, C6, C7
Tina C3, C4, C5
Zack C3, C4
Complete Time Attack mode on the default settings to unlock an alternate costume with the following characters. If available, the next alternate costume for that character will be unlocked when Time Attack mode is completed with them again.
Ein C3, C4
Genfu C3, C4
Leon C3, C4
Spartan-458 C3, C4, C5, C6, C7
Biolab Core stage
Complete Story mode.
Bonus system announcer voices
In the options menu, you can choose different voices for the system announcer. To unlock additional voices, enter Sparring mode and bring up the sparring menu. Select Exercise and you will be prompted to run through an extensive moves list. Complete the moves list to unlock that character's voice as a system announcer. Complete Exercise mode with all default and bonus characters to unlock Alpha-152's system voice.
Easy wins with Jann Lee
Try to land a critical punch or kick to the enemy's head. If not accomplished, make use of quick countering or blocking to land a firm blow. Then when your enemy is hit off balance for a few seconds, keep throwing random critical blows to the head region mainly, and mix it up slightly to the body and legs. If you can do this and include fast combos in between your rhythm, you should be able to keep the enemy off the ground desperate for making successful blows. You should be able to do this technique with simple combos. Make sure that your rhythm is broken, meaning attack at different times without staying in a similar pattern and keeping your blows mostly critical. If you can do this a lot, you should also be able to switch it up with fast combos making it almost impossible for your opponent to counter. Remember to execute critical blows to the head mainly, mixed with fast combos and quick blows to the body. Keep your rhythm broken so it is impossible to counter (no repetition or repeating the speed of blows), and make sure to keep your guard up. Do not allow the enemy to hit you unexpectedly, or they may confuse you with the same trick. Try to at least counter when you lose balance in the match.
Accomplish the indicated task to get the corresponding number of Gamerscore points:
Achieve a Bronze Star (10 points): Defeat someone with a 10-14 win streak in Dead Or Alive 4 Online.
Achieve a Gold Star (30 points): Defeat someone with a 20+ win streak in Dead Or Alive 4 Online.
Achieve a Silver Star (20 points): Defeat someone with a 15-19 win streak in Dead Or Alive 4 Online.
Unlock Ein (10 points): Complete Story mode with Hitomi.
Unlock Gen Fu (10 points): Complete Story mode with Eliot.
Unlock Helena (20 points): Complete Story mode with all characters.
Unlock Leon (10 points): Complete Story mode with Zack.
Unlock Spartan-458 (20 points): Complete Story mode with Helena.
Unlock Tengu (20 points): Complete Time Attack mode with all default and hidden characters.
The following are secret achievements, but will earn no Gamerscore points:
Get a D rank in Dead Or Alive 4 Online.
Get an E rank in Dead Or Alive 4 Online.
Get an F rank in Dead Or Alive 4 Online.
Lose 5 consecutive online matches.
Lose 10 consecutive online matches.
Lost 20 consecutive online matches.
Halo reference in the game
Select Spartan-458 and play on the Gambler's Paradise stage. During the match, a Warthog with Marines will appear on the road.
Hidden goof rewards
Some of the game's secrets shown in the achievements list are actually goof rewards. These vary from Loss Streaks to Rank Demoting.
Enter 99 as your age in your profile to make the female characters breasts bounce nicely.
Nassau Station stage
Complete Story mode with Helena.
Play as Ein
Complete Story mode with Hitomi.
Play as Gen Fu
Complete Story mode with Eliot.
Play as Helena
Play as Leon
Complete Story mode with Zack.
Play as Spartan-458
Complete Story mode with Helena.
Play as Tengu
Complete Time Attack mode with all default and hidden characters.
Tatami Mat stage
Unlock all costumes and system voices and Complete Story mode with all seventeen characters.
Complete Story mode with any character.
Bug/Glitch: All my data gone. Well it happend to me. I turned my xbox on today and all my DOA data was gone. I read about the glitch and know to load my profile before loading the game. Does anyone know if there is anyway to get it back? I have a memory card and a harddrive I think next time I will back up my data to the memory card just to be safe. Has this happend to anyone else. Oh btw my wins and losses online stayed but I am sure those are stored on the servers. The wierd thing is that when I went to bed last night I was a C- now im a C+ I guess it just reset my ranking online , But kept my wins and losses.
Fix/Solution: If you notice that your data is missing IMMEDIATELY turn off your Xbox 360 BEFORE IT GETS A CHANCE TO SAVE OVER YOUR GOOD DATA. If you played around for a bit before turning it off, you lost your save game. It happened to me, it sucks. Load your profile BEFORE inserting the disc in the tray (this is the old fashioned way of game booting - make sure auto-retrieve of profile is enabled on your dashboard).