The two appear exclusively in Sonic Underground.
Sonia and Bartleby both grew up in rich conditions. The two were engaged at the beginning of the series, although Sonia later called off the engagement for unknown reasons. It may have been because Sonia became a member of the Freedom Fighters while Bartleby was an aristocrat.
Although narcissistic, Bartleby has been shown to care for Sonia's wellbeing. He disliked the fact Sonia risked her life by becoming a Freedom Fighter. He thought Sonia's brothers, Sonic and Manic, were a bad influence on her.
Bartleby was eventually announced Robotnik's enemy. He was put on trial and purposely found guilty. Bartleby was willing to risk roboticization to protect Sonia, and told her not to rescue him as she could be captured. As it turned out, the trial was a plot to lure Sonia and her brothers into a trap. The Sonic Underground siblings managed to save Bartleby and avoid the trap set by Robotnik. Sonia and Bartleby said goodbye to each other outside of an airport, and Bartleby went into hiding while Sonia continued as a Freedom Fighter.
Although not a very popular ship for Sonia, Bartonia has quite a few supporters. Shippers of this pairing feel that Bartleby gets undeserved hate.
On AO3, the pairing is the second most written ship for Sonia and the only ship for Bartleby. The ship, however, is rare, as any ship involving Sonia is uncommon on the website.
- bartonia tag on DeviantArt
- bartleonia tag on DeviantArt
- bartlebyxsonia tag on DeviantArt
- soniaxbartleby tag on DeviantArt