Koujiro Rinko

Professor Koujiro Rinko is a scientist, former love interest, and co-worker of Kayaba Akihiko. She attended Touto University in Japan and was a part of Shigemura Lab in the Electrical and Electronic Engineering Department.

Background
Koujiro Rinko met Kayaba Akihiko in her first year of college at 18 years of age, when she invited her senpai to go swimming. Kayaba was 19 years of age at the time and a second year.

Soon afterwards, Koujiro Rinko began working on the SAO project, unaware of Kayaba's mastermind plan. Ten years later, the first VRMMORPG Sword Art Online was released.

Sword Art Online
She initially helped in the development of SAO, when the SAO incident occured, she was the only person who guessed where Kayaba was, and without telling anyone and avoiding the police, she decided to confront Kayaba in his hidden mountain cottage with the intent to kill him, but she was not able to do so and instead helped maintain Kayaba's physical condition when he dived into the game for long periods of time. After the incident, the police found the cottage where both of them stayed. While Kayaba had already died after digitizing his brain to the network, Rinko was arrested by the police and awaited for her trial.

ALfheim Online
After the ALO incident, Kirito wanted to find out more about Kayaba and his World Seed. He got hold of Rinko's email address and asked if they could talk. A week later Rinko replied, and she went to Kirito's house, and they went to a coffee shop near a Tokyo station. Apparantly she was released on bail from her trial and later acquitted.

Project Alicization
It has been 2 years since the SAO incident. Rinko has apparantly moved to San Francisco, America. She has been invited to do a top secret research on FullDive technology from Kikuoka Seijouro, but has been reluctant to accept the offer until one day she received a long mail from an unexpected person which turned out to be Asuna. After learning of Asuna's situation, she agreed and contacted Seijouro that she would be accepting the invitation. Rinko and Asuna, then disguised as Rinko's assistant, then went to the RATH hidden base, the Ocean Turtle. There they witnessed their research on the «Soul Translator» and the reason why Kirito was secretly transferred to this facility.