The design for Kula Diamond was aided by the input of the female staff to properly depict a 14-year-old girl with "appropriately girlish" gestures.

Hinako's design was initially based on the protagonist of the manga Jarinko Chie, who used sumo moves. The supervising designer, however, succumbed to insistent requests to use "a debutante" and Hinako gradually transformed into a wellborn young maiden. She was also originally going to fight barefoot, which was also dropped. The only thing that remained from her original concept was the athletic tape on her fingers.

Vanessa was originally planned to appear as a playable character rather than a striker character in The King of Fighters '99, but was cut from the roster due to time constraints.

Whip's Desert Eagle was completely censored in international versions of the game. Her scene in the Ikari Team ending was also altered to not have her shoot Zero in anger.