Complete Story mode to unlock the Lab stage.

Unlock the following costumes by performing the corresponding tasks:

COSTUME - HOW TO UNLOCK
Christie Swimsuit - Clear the Legend course (solo match) in time attack mode with Christie without using a continue.
Kasumi Black Suit - Clear the True Kasumi chapter in Story Mode.
Kasumi Kimono - Clear the Kasumi vs. Christie battle in the True Kasumi chapter of story mode.
Lisa Swimsuit - Clear the Legend course (solo match) in survival mode with Lisa.
Tina Swimsuit - Clear the Legend course (solo match) in Arcade mode with Tina, without using a continue.

Complete command training in training mode with every character.

Change the following by performing the corresponding tasks at the costume selection screen:

Hair style
Press and hold LB/RB with any Hold/Punch/Kick button for different hair style

Accessory(Hat/eyewears etc.)
Press and hold LEFT/RIGHT with any Hold/Punch/Kick button

Panty
The Hold/Punch/Kick each correspond to different panty.

Unlock the following courses by performing the corresponding tasks:

COURSE - HOW TO UNLOCK
Legend Courses - Clear the Master course in Arcade mode, survival mode, or time attack modes.
Master Courses - Clear the True Fighter course in Arcade mode, survival mode, or time attack mode.
True Fighter Courses - Clear the champ course in Arcade mode, survival, or time attack mode.

ACHIEVEMENT - HOW TO UNLOCK
Fighting Entertainment (10 points) - Have your first fight outside of Training or Versus modes.
Rivals (20 points) - Register 5 fighters in your Fight List.
Rival Rumble (20 points) - Fight online 10 times.
Rival Rampage (30 points) - Fight online 100 times.
DOA5 Is My Life (50 points) - Fight online 1000 times.
My Fight, My Rules (10 points) - Create your own online lobby.
Get out there and Fight! (10 points) - Play a Lobby match.
Fighting For Real (10 points) - Play a Ranked match.
Jump In (10 points) - Play a Simple match.
Gesundheit! (20 points) - Trigger the Special Danger Zone in The Show.
Tango Kilo November (20 points) - Trigger the Special Danger Zone in Hot Zone.
You Asked for It! (20 points) - Fight 10 people through invitations.
Anybody, Anytime, Anywhere (30 points) - Fight 50 people through invitations.
First Throwdown (20 points) - Send a Throwdown Challenge to someone in your Fighter List.
Akira Yuki (20 points) - Unlock Akira.
Sarah Bryant (20 points) - Unlock Sarah.
The Ultimate Hyper Clone (50 points) - Get all titles and unlock Alpha-152.
Arcade Cleared (10 points) - Clear 1 course in Arcade mode.
Arcade Master (30 points) - Clear all courses in Arcade mode.
Time Attack Cleared (10 points) - Clear 1 course in Time Attack mode.
Time Attack Master (30 points) - Clear all courses in Time Attack mode.
Survival Cleared (10 points) - Clear 1 course in Survival mode.
Survival Master (30 points) - Clear all courses in Survival mode.
Fledgling Fighter (20 points) - Fight 10 Versus matches.
The Fight Never Ends (30 points) - Fight 100 Versus matches.
Training Hard (20 points) - Play Training mode for 1 hour.
Exercise Newbie (20 points) - Perform all moves in Command Training.
On the Edge of Your Seat (10 points) - Play Spectator mode.
Fighter, Know Thyself (10 points) - View your results in Fight Record.
Ahhh, Memories (10 points) - View your photos in the Album.
Say Cheese! (10 points) - Take a photo in Spectator mode.
How Do I Fight? (10 points) - Display the Move List.
How Do I Fight Like a Pro? (10 points) - Display the Move Details.
A Fight to Remember (10 points) - Save a replay.
Safety First (10 points) - Turn Danger Zones off on the Stage Select screen.
Fighting in Style (50 points) - Unlock all costumes.
First Tag Team (10 points) - Play Tag Battle.
The Power of Two (30 points) - Perform 50 kinds of character-specific tag throws.
Blow 'Em Away (10 points) - Successfully land a Power Blow.
Down You Go (10 points) - Successfully attack during a Cliffhanger.
Cliffhanger Comeback (10 points) - Successfully block an opponent's attack during a Cliffhanger.
I Read Every Move (20 points) - Win without taking any damage.
Failure Teaches Success (20 points) - See all characters' losing poses.
Insomniac (20 points) - Watch all movies in Story mode without skipping any of them.
DOA5 Master (100 points) - Unlock all achievements.
The Curtain Rises (10 points) - Clear the Prologue in Story mode.
Ninja Battle (20 points) - Clear "Kasumi - Part 2" in Story mode.
...And Then THIS Happened! (30 points) - Clear all chapters in Story mode.

Unlock the following characters by performing the corresponding tasks:

CHARACTER - HOW TO UNLOCK
Akira Yuki - Defeat him in Story mode.
Alpha-152 - Earn 300 titles.
Gen Fu - Complete Eliot's Story mode chapter.
Pai Chan - Earn 100 titles.
Sarah Bryant - Defeat her in Story mode.