<P> Isabella Garcia - Shapiro (voiced by Alyson Stoner) is a Jewish Mexican girl . She is one of the brothers' best friends and has an obvious crush on Phineas Flynn of which he is unaware, though he has shown he cares for her from time to time . She is known for the catchphrase, "Whatcha doin'?" and is the leader of the Fireside Girls troop 46231 . The troop often helps Phineas and Ferb in their projects . She is named after series creator Dan Povenmire's oldest daughter . </P> <P> Stacy Hirano (voiced by Kelly Hu) is Candace's best friend . She is of Japanese heritage . Stacy is shown to be annoyed by Candace's constant attempts to bust Phineas and Ferb, and would prefer to just have fun with the inventions; she also occasionally gets annoyed with Candace's gushing about her relationship with Jeremy . During the episode "Happy Birthday, Isabella", she finds out about Perry's secret Identity but doesn't lose her memories afterwards . </P> <P> Jeremy Johnson (voiced by Mitchel Musso) is Candace Flynn's crush and later boyfriend . His age is sixteen, a year older than Candace . He works at Mr. Slushy Burger (sometimes named Mr. Slushy Dawg). In "Summer Belongs to You," it was confirmed that he and Candace had become boyfriend and girlfriend; toward the end of the episode, they kissed . He also has a band called "The Incidentals ." </P> <P> Major Francis Monogram (voiced by Jeff "Swampy" Marsh) is one of the heads of the O.W.C.A. (Organization Without a Cool Acronym) Department and Perry the Platypus' boss . He usually appears in a Nehru jacket on a giant screen giving Perry instructions for his next mission to stop Dr. Heinz Doofenshmirtz's endless attempts to take over the Tri-State Area . His uniform prominently features the initials "MM ." He has a monobrow and wears a toupée . Sometimes, he is shown to have a lack of details about what Doofenshmirtz is up to, and orders Perry to go stop it as usual . Just like Doofenshmirtz, he has appeared in every episode of the series to date except, "Isabella and the Temple of Sap ." </P>

Who does the voice of jeremy on phineas and ferb