Secret Costume (Japanese Version)
Description: Collect all five gems from the jewelry thief and then finish the game to get the secret costume:

Kazuya	At the jewelry shop, give her a heat-restoring pack
Yuko	At an overlook of the tunnel bridge, give her an umbrella
Akira	At the mall parking lot in the area with the restaurant, give her a ride
Kana	At the gymnasium exterior, talk to her
Yuji	At a truck near a partially sunken overpass, give her any food item

Collect Five Gems : Secret Outfit
Description: Each character can collect a gem from the Jewelry Lady :

Amber	Give the Jewelry Lady an umbrella
Issac	Give the Jewelry Lady a ride in your taxi
Ivan	Give the Jewelry Lady some food
Josh	Give the Jewelry Lady a heating pad
Paige	Chat to the Jewelry Lady at the gym

If all 5 characters perform the above task, you will receive 5 gems total from the Jewelry Lady. When you completed the game with all 5 gems in your inventory, you will unlock a secret outfit.

Secret Costume (North American Version)
Description: Collect all five gems from the Jewelry Lady and then finish the game to get the secret costume:

Josh	Give her a heating pad
Amber	Give her an umbrella
Issac	Give her a ride in your taxi
Paige	Talk to her at the gym
Ivan	Give her some food

Special Costume
How to unlock: Collect all 5 gems from the jewelry thief.

Relationship with Stephanie
If you talk to Stephanie good and not mean she will think you as her boyfriend but if you dont she will think you as her best friend.