Sue is first mentioned in chat logs by her brother Kazuma and in an argument between King and Toroko. Because Sue is wanted by the Doctor, King wants to turn her in before the Doctor attacks the village to try and get her himself. He feels this is an unfortunate plan but doesn't care much for Sue's safety, since Sue isn't native to the village and seems to hate everyone in it besides Toroko. On the other hand, Toroko is close friends with Sue and refuses to give King the key to Arthur's House, where Sue is staying.
Sue is first seen in the Egg Corridor, trying to get past Igor so she can examine the eggs to see if any of them are ready to hatch a Sky Dragon that she and the others can escape the island with. Igor easily knocks her unconscious and puts her in the room containing Egg #00. After Quote defeats Igor and wakes her up, she asks if he saved her. No matter what Quote says, she acts angry and dismissive of him before realizing that the egg in the room is ready to hatch; all it needs is a password that she's sure her brother Kazuma could figure out. She goes back to Arthur's House but, when she arrives, King and Jack capture her and lock her in the village cage, hoping to give her to the Doctor in exchange for Toroko, who was mistaken for her and kidnapped by Misery.
While in the cage, Sue asks Quote to go to the Bushlands to rescue Kazuma for her. While he's doing that, she tells King and Jack the Doctor's plan to turn all the Mimiga into his personal army using Red Flowers. The two of them let her free, allowing her to go back to Arthur's house to meet the newly arrived Kazuma and Professor Booster. When King enters as well, she introduces him as a friend of her's, indicating that she's starting to warm up to the other villagers.
After the Doctor obtains the Red Flowers and Quote is sent to the Labyrinth by Misery, Sue and all the other Mimiga are taken to the plantation to start cultivating the plant. However, Sue is put in a prison along with Jack and Mahin. After Quote is knocked out and imprisoned in the same cell, he wakes up to find that he and Mahin are the only ones left in the jail. Mahin explains that Sue was taken away as Quote was being put in and stuffed something in his pocket as she passed by him.
After the Doctor is defeated and Quote goes up to the island's core, Misery stops him and teleports Sue into the room, threatening to hurt her if the core is touched. Both of them are then attacked by the incorporeal essence of the Doctor, transforming Sue into a violent human/mimiga hybrid. After the Undead Core is destroyed, Sue turns back to normal (or, rather, a full, non-enraged Mimiga). With the island now sinking, she runs out to the Balcony and, seeing no other means of escaping, jumps off the edge and hopes for the best. She is caught in mid-air by Kazuma's Sky Dragon and returned to her family. In the ending, Itoh and presumably her mother and brother construct a machine to transform herself and Itoh back into humans. Although the machine seems to work, they both sneeze after a couple seconds and turn back into Mimiga. It is unknown whether or not they ever successfully turn back.
- Sue's Halloween design is a reference to the character Princess Peach from the Super Mario Bros. series.
|General||Egg Corridor (Egg Corridor?) • Missile Launcher • Sky Dragon • ID Card|
|Characters||Sue Sakamoto • Robots • Cthulhu|
|Enemies||Critter • Beetle • Behemoth • Basu • Basil • Time Bomb • Dragon Zombie|
|Bosses||Igor • Sisters|
|Cave Story Characters|
|Protagonists||Quote • Curly Brace • Sue Sakamoto • King • Toroko • Kazuma Sakamoto • Professor Booster • Itoh • Momorin Sakamoto|
|Antagonists||Doctor • Misery • Balrog • Ballos|
|Others||Tetsuzou Kamadani • Jack • Mahin • Kanpachi • Sandaime • Arthur • Cthulhu • Santa • Chako • Malco • Colons • Jenka • Puppies • Chaba • Dr. Gero • Nurse Hasumi • Littles • Chie • Zett • Megane • Shovel Brigade • Numahachi • Ballos|
|Races||Robots • Mimiga • Humans • Cthulhu • Witches • Gaudi • Droll|