- "I saw you fuck that Bitch on the monitor. Were you trying to rub my face in it?"
- — Joni to Luis Lopez
Joni is a female security manager who works in Maisonette 9 alongside Luis Lopez and Dessie. She appears to have previously been on medication of some sort, as on one occasion she tells Luis she should "probably go on meds again".
Events of TBoGT
Joni works with Luis as part of the "Club Management" side-missions. Luis keeps in contact with her via headset whilst scanning the dance floor from the security room for trouble, telling Luis to check out certain areas where she sees disturbances.
Occasionally, Joni will call Luis to her office and offer Luis sexual favors such as a sexual dance, a blowjob or sex. Sometimes she will scold Luis if the player had sex with other women.
- Joni constantly teases Luis about his penis size. At the beginning of the club management missions, she will make comments such as "you have a great body L, shame about the little guy!", "Do steroids make your balls shrink or were they always like that?", and "So you WERE overcompensating."
- The physical disc version of Grand Theft Auto: Episodes from Liberty City comes with a map of Liberty City that features a poster of Joni on the other side.
- Joni's appearance differs between her artwork and her appearance in the game, as her artwork depicts her with thinner lips and differently shaped eyes.