Ten years prior to the events of the game, Quote and Curly Brace were sent to the floating Island during the conflict over the Demon Crown. Unlike the other robots sent to the Island, Quote and Curly were ordered to destroy the Demon Crown rather than recover it. As they arrived later than the other robots, much of the Island was in shambles by the time they arrived, with destruction and carnage everywhere. By the time they found the Demon Crown, a human - Miakid - had already found it first and unleashed its power. Quote and Curly battled him and successfully wounded him but were eventually defeated, and were incapacitated for the next ten years.
Curly reawakens some time after the ten years from their battle, with complete amnesia (remembering only her name), somewhere in or near the Sand Zone, where she stumbled upon four orphaned Mimigas called the Colons. She decided to take them as her adopted children and lived peacefully until the Doctor's minions began roaming around the Island, kidnapping Mimigas. Before long, Quote arrived in the Sand Zone, where he stumbled upon Curly and the Mimigas she's protecting. Curly mistakes Quote for a "Killer Robot" and attacks, but ended up getting beaten. Upon seeing Quote spare her "children", she realized Quote was not trying to eliminate them.
Soon after Quote's departure, Misery arrives in the Sand Zone and teleports the Colons to the Plantation. She then sends Curly to the Labyrinth where she is treated for her injuries by Dr. Gero, who heals her. She then strikes out for the Boulder Room, where she meets up with Quote. After a scuffle with Balrog, the two continue further into the Labyrinth together untill they come across and defeat the Core. Unfortunately, water then fills the room, and Quote would have drowned, had Curly not given him her Air Tank.
Curly later washed up in the Plantation, where she was found by Cthulhu. She had once again become afflicted by amnesia, no longer remembering even her name. Quote then found her, and traveled to the Mimiga Village Graveyard to find a mushroom to restore her memory - Ma Pignon. This restores all of her memory, including Quote's name (which she reveales for the first time in the entire game). Curly then gives Quote an item known as the Iron Bond. The Iron Bond's item description refers to Curly as "The only person you would trust your back to."
Curly appears once more in Sacred Grounds. Unlike all other times, she has a Nemesis, as opposed to her usual weapon, the Machine Gun. Quote straps her to his back with the Tow Rope and together they defeat Ballos. As Ballos dies, the walls begin to close in, but she and Quote are rescued by Balrog. The three of them then go and live together someplace nice.
Curly is battled alongside The Colons in the Sand Zone Residence. She is completely impervious to the Missile Launcher, as she will put up an energy shield that deflects Missiles if Quote fires any at her. The Colons will also get in the way and will block shots, although they can be knocked out to allow a clear shot at Curly. Curly attacks by charging her Machine Gun and firing a barrage of shots at Quote, then repeating. She can shoot up as well as horizontally, so she can hit Quote if he tries to jump over her. The best strategy is to attack her until she finishes charging, then dodge her attack, then repeat. Any weapon except the Missile Launcher will work in this battle, although the Bubbler and the Fireball are preferrable to the Polar Star because of their higher damage.
- Level 3 Machine Gun
- Polar Star (If traded Machine Gun to Quote for it)
- Level 1 Nemesis (Sacred Grounds only)
- Curly displays the ability to create an energy shield (possibly the Air Tank's shield) to deflect Missiles during her battle with Quote, but never does this when fighting enemies afterwards. Quote also never gains this ability. It's unknown how Curly was able to use this ability.
- In the beta-version of Cave Story, Curly Brace was the name of the protagonist, but had Quote's sprites with a different color-scheme.
- Curly, like Quote, is named after a punctuation mark used in programming.