Oldcodex was founded on October 21, 2009, by members Ta_2 (Tatsuhisa Suzuki) and R.O.N, who used to work with Ta_2 on his past solo projects.
They were accompanied by other members from another one named "ROSARYHILL", including R.O.N himself, YoHske and sae, though the last two did not stay from February 15, 2010, onward.
This announcement came shortly after Shūkan Bunshun reported that he was involved in an extramarital affair with a female work associate.
"[4] On December 27, 2021, it was announced that Oldcodex was set to disband following the release of the theme song for the upcoming Free!
[5] Ta_2 and Yorke both shared their feelings about the announcement on the exclusive fanclub site, which was closed down at 12PM local time on March 1, 2022.