As the only one among her friends to obtain the rank of Keyblade Master, Aqua is assigned to monitor Terra and Ventus as she combats dark creatures known as the Unversed.

Later in the design process, Nomura became concerned that Aqua would not be popular, which drove his decision to make her more distinct in her personal bravery and combat abilities.

The character received mixed reviews from game critics upon her debut, citing boring plot lines and unenthusiastic voice acting combined with weak combat skills.

Kingdom Hearts II Final Mix also contains an additional cutscene showing Aqua's Keyblade and armor to be stored in the "Chamber of Repose", a hidden room in Hollow Bastion frequented by Xemnas.

[5] Aqua later reunites with her friends at the Keyblade Graveyard, where Terra is possessed by Xehanort and Ventus sacrifices his own heart to prevent the creation of the χ-blade.

[6] Aqua uses Eraqus's Keyblade to transform the Land of Departure into Castle Oblivion, leaving Ventus's catatonic body there before confronting the possessed Terra at Radiant Garden.

[9] In the game's secret ending, she meets Ansem the Wise at the realm's edge and learns from him about the heroics of Sora, whom she had encountered as a young boy during her travels.

Nomura felt the open back of Aqua's outfit presented at the Tokyo Game Show 2009 was too revealing and modified the design to be more conservative.

[1] From the beginning of Kingdom Hearts Birth by Sleep's development, the staff decided its story would have three plot lines centered around three different characters, with Aqua's being the last one written.

[20] Aqua's character has received mixed response from video gaming publications, with initial comments focused on her brief appearance in Kingdom Hearts II.

[26] Kevin VanOrd from GameSpot gave praise to Aqua's character, based on her personality and how it contrasts Ventus's, as well as Holland's voice acting.

[28] On the other hand, Bob Miur from Destructoid found her gameplay appealing due to how it contrasts previous fighting styles seen in the Kingdom Hearts series.

[36] Kimberly Wallace from Game Informer said Aqua was one of her favorite characters due to "her selflessness and determination to save the world, and getting some resolution to her story was satisfying".

[38] In a general analysis of the portrayal of the franchise's female characters, Polygon saw Aqua as possibly the strongest one due to how central is her role in Birth by Sleep when compared to weaker ones like Kairi, Namine or Xion.

Her return in Kingdom Hearts III was also praised,[39]having both her working trauma experienced during her time in the Realm of Darkness, and the goal of saving her friends who she had failed to protect 10 years earlier.