|Class||NPC Evolved AIDA|
|Character Voice||Ami Koshimizu|
|First Appearance||.hack//LINK: Twilight Knights|
- "AIDA stole data from humans just for the purpose of living, of evolving. Because of AIDA, Haseo, Atoli, everyone suffered... But what should I, who was born from their suffering, do in this world?"
- — AIKA —
She closely resembles both Saika and Ayaka but with longer and green colored hair and there's a star shape in her eyes. She wears white princess dress with blue bracelets and golden tiara.
AIKA's "AIDA spots" are brightly-colored, different from the black ones that appear around normal AIDA.
She's kind, soft-spoken, polite, and yet shy at the same time. To be more exact, she's a complete opposite of Saika who was more straightforward and rough. She's too modest and pessimist of herself, especially whenever it comes to the fact that she's not a human but an AIDA and she would cry and run away whenever she pointed this out before even hearing everyone's opinion, making Saika protective of her and treat her like her little sister. She cares deeply for her fellow AIDA, stating that AIDAs are not toys, and also Saika and Tokio, the only people whom she opens up with and she would try her best to be helpful for them. She harbours feeling for Tokio, but never expresses it because she's aware of Saika's growing feelings for him.
Like AIDA, AIKA has an interest in but a poor understanding of life outside of her environment, struggling to pronounce words such as "hamburger" or even "computer." She is also deeply interested in her reason for existing.
In 2014, AIKA was created as an event NPC in Jyotaro Amagi's online game Akashic Line, subconsciously modeled after his late aunt Ayaka Amagi. In 2014, during the game's closed beta test, Tokio Kuryuu succeeded in rescuing her to clear an event. For an instant, he was successfully Real Digitalized by Amagi's test program, becoming the only Doubleware to be discovered by the game. Although he did not understand this at the time, this direct contact left a lasting impression on both him and the NPC.
In 2017, she became fused with benevolent AIDA, retaining the memories of the NPC and the personality of the AIDA, forming a completely new type of AI. Eventually, she was discovered and retrieved by Saika Amagi in order to find her brother.
After Tokio failed to prevent Shino from being PKed in the alternate 2016 generated by the Akashic Records, AIKA comforted Tokio directly for the first time when he was sulking and blaming himself, offering to give him a power in order to protect people he holds dear and Tokio accepted it. AIKA guides Tokio to the same dungeon that he experienced in his dream that turned out created by his own memories. When Tokio reached the end of the Dungeon, they encountered a bug PC that manifested from Tokio's guilt for not able to save Kite back at 2010. When he was seemingly swallowed by the PC, AIKA told him not to lose to the darkness of his own heart and think about the people he head encountered. Resolved to protect and save those he holds dear, AIKA granted Tokio the Xth Form before he fought the bugged Kite PC.
In 2017 when Haseo encountered AIDA and for the first time summoned Skeith, AIKA briefly surfaced in Saika's mind and pleaded to Haseo not to destroy the AIDA. However, Haseo ignored this and destroyed the AIDA anyway.
Shortly afterwards, Saika finally introduced AIKA to Tokio and she temporary become Tokio's guide during Saika's absent. She assists Tokio in his mission with Pi by calming down the AIDA that was about to infect Pi, revealing herself to be an AIDA. After Haseo won the Demon Palace Tournament and defeated Kuhn, AIKA warned Tokio that she sensed AIDA within Haseo. However, instead of the AIDA controlling Haseo, the AIDA was unable to free itself from Haseo due to his Epitaph's power. She then assisted him again and Pi at Moon Tree @home by calming down the AIDAs that infected all members of Moon Tree.
Back at 2020, after being unable to save Jyotaro Amagi's consciousness from the impact of Real Digitalization, AIKA comforts the saddened Saika for Jyotaro being lost in front of her eyes. When Saika revealed her guilt for involving Tokio, AIKA forcefully dragged her to talk with Tokio since she actually likes him, much to Saika's protest but she's unable to resist. AIKA watched from afar as Saika burst into tears by Tokio's side after Saika revealed all of her sadness that she have been kept.
She made her last appearance at the final battle with Aura who was now known as the Queen of Demise. As Tokio's comrades succumb to Aura's song one by one, AIKA told him that she finally knew what her purpose really was and assured him that Aura will surely remembers her memories and bid him farewell as she called him her hero, making Tokio remember AIKA as the princess that he saved from the event in the Akashic Line in 2014. She flew towards Aura as she remembers Saika and Tokio and their promise to spent time together in real life before exploding into pieces of data, while leaving behind only her broken Chim Chim doll, then spreading out into AIKA bubbles into Aura's heart. She's last seen presumably within Aura's mind with Aura in her child form, holding her hand before they disappear together.
In .hack//Integration (Alternate Timeline) during the party in Net Slum, Helba found AIKA's Chim Chim doll that Tokio fully regenerated and suggested that AIKA might as well still exist somewhere in The World, but is still unable to show herself for some reason.
- AIKA is mentioned on the Innocent Call drama CD as one of the AIDAs who didn´t attend to their meeting.