Stacy Hirano is Candace Flynn's very enthusiastic best friend in Phineas and Ferb. She usually convinces Candace to participate and enjoy the moment instead of trying busting her brothers.
Stacy Hirano is the daughter of Dr. Hirano and an unnamed father. Sometime in her life, likely before or during the third grade, Stacy met Candace Flynn and they immediately became the best of friends. How they met is currently unknown. Stacy is constantly supporting Candace to bust her brothers, though it is revealed through her conversation with Jenny that she wants Candace to "give up this busting thing once and for all." Stacy is the cool head between her and Candace, and seems to be the only one that can calm Candace down in any given situation that Candace is stressed in, whether it pertains to Jeremy or busting Phineas and Ferb. Stacy herself doesn't have any issues with Phineas and Ferb, once even insisting Candace goes on the Mix-n-Mingle machine because she believed it would help Candace. She became The Disco Miniature Golfing Queen while playing miniature golf with Phineas and Ferb while trying to bust them for Candace when Candace was sick.
During the Summer Rocks Festival Candace introduced Stacy to Coltrane. During the festival they started showing mutual feelings for each other. Their current relationship status is unknown. It is revealed in that in the future Stacy becomes the President of Uruguay.
When Phineas and Ferb go around the world to try and make the longest day of summer ever, they meet Stacy's cousins and other family members when stopping in Tokyo. This shows that Stacy has some Japanese descent in her family tree.
Stacy also has a purple bracelet on her left wrist, and light blue stockings paired with black dress shoes on her legs. She also has light skin, brown eyes and long black hair. She also has a resemblance to Ginger, who is one of the Fireside Girls.Stacy, in a similar way to Candace, has her own set of trademark clothes. This includes a turquoise t-shirt, along with a blue skirt. She wears a blue bow on her head which is her trademark look, according to Candace. Candace and Coltrane happen to like her bow. According to Candace, the bow makes Stacy look cute. As to how the bow is in her hair, its actually on a hairband, seen when Candace wakes her up one morning by calling her on the phone. She is also slender.
- Sometimes, her name is misspelled "Stacey".
- Stacy can sing and play the guitar, also she played left-handed as seen in "Phineas and Ferb Get Busted!".
- Hirano is one of 24 wards (districts) that make up the city of Ōsaka, Japan. It literally means "level field". Her surname was probably chosen due to her family/descendants being Japanese ("Phineas and Ferb Summer Belongs to You!").
- Stacy and Candace are winners of a contest to meet the rock band The Bettys. ("Ready for the Bettys")
- Closed Captioning occasionally misspells her last name as "Gerado" ("I, Brobot").
- According to Speed Demons, Stacy once spilled grape juice on Linda Flynn's sweater which Candace has borrowed without asking.
- The first episode that focused on Stacy is "Put That Putter Away". Stacy likes to have fun just like Phineas and Ferb do.
- Stacy enjoys shoes, as seen in "Day of the Living Gelatin" when she makes her gelatin in the shape of shoes, and in "Elementary My Dear Stacy" when she loves to go shopping for shoes in London.
- She has a poster of the Bettys in her room, then later of the series a poster of the Paisley Sideburn Brothers.
- She is one of the few people to notice a pattern, and claims that she is the only person not to say "Where's Perry?" in "Bad Hair Day", although in she had already said it once in "Put That Putter Away". "Put That Putter Away" may have taken place after "Bad Hair Day".
- In "The Baljeatles" it was revealed that Jeremy's nickname to Stacy is "Staceroo". Also, Candace often calls her "Stace", like in "Elementary My Dear Stacy".
- Her name in Japanese is ステイシー平野 (suteishī hirano).