Sgt. Garcia-Shapiro

Sgt. Buck Garcia-Shapiro, is Isabella's older cousin. He is currently a Sergeant in the United States Army, serving for five years. Currently, he is home with his spouse, Maria Garcia-Shapiro, after completing his mission in Iraq. If not in combat, Buck would see Monty Monogram. They are best friends. Buck is also friends with Jeremy Johnson, Coltrane, and most of his adult friends that went to school with him. Candace Flynn has interest in him, because of his service in the military, though he is mostly ring use to aid her in busting Phineas Flynn, and Ferb Fletcher. He would rather not bust them because he realizes that their projects are not a threat to society, in fact it generates a more positive society. Sometimes, he would even help Phineas and Ferb, in an effort to contribute to groups and the events in Danville.

Isabella Garcia-Shapiro
He is the older cousin of Isabella. They hardly see each other, because Buck is on duty. He would send letters to her, with an occasional item in a package. They would reunite at times Buck is off duty. Isabella is proud to have him as a cousin, where she could rely to him for help.

Monty Monogram
They have many stuff in common, which establishes a close relationship. Both of them have gymnastic skills, and have dads that are officers. Their dads are best friends with one another also, making this friendship perfect. Once, they became a performing duo at a carnival. Then they did some skydiving. Both of them are members of the O.W.C.A. (Buck joins once he finishes his missions in the military), and would be a crime fighting duo.

Jeremy Johnson
Buck and Jeremy are friends because they both like rock music. Both of them would be committed into Candace's problems with Phineas and Ferb, though they would just engage with their projects. There are running gangs where they would get together in songs at certain episodes.

Monty Buck
Buck joins Monty and Agent P a.k.a. Perry the Platypus, to stop Dr. Doofenshmirtz from capturing whales in the Atlantic Ocean, as part of the development of the Whaleinator.

B*U*C*K*
He aids the citizens in need after a hurricane. Afterwards, he joins Jeremy in a fundraising concert.