In Girls Just Wanna Have Fun, Jimmy and Spinner Mason were plotting to beat Marco (who is introduced in this episode, albeit without any lines) in the break-dancing competition at the 1980s themed dance because the prize was tickets to a Toronto Maple Leafs Game. They tried to sabotage each other but this only allowed Marco to win. In spite of this, they both eventually became close friends with Marco.
In Drive, Craig invited Jimmy, Spinner, Marco and Sean Cameron to stay over at his house while his stepfather Joey Jeremiah was away for the weekend. However, Jimmy, angry that Sean was invited, did not attend.
In Fight for Your Right, both Craig and Marco were impressed by the new clothes that Jimmy's father Jermaine Brooks had bought him as a belated birthday present. Craig asked him if he had won the lottery while Marco wondered if he had left anything on the racks. On the basketball court at lunch, Marco was impressed with Jimmy's new shoes, which he always received for his birthday, and jokingly asked him if his parents would adopt him. Jimmy told him that they already had another son, Spinner, who had "worn serious grooves" in his couch. Marco then said that if Jimmy's parents did love Spinner so much, they should take him clothes shopping too since he had seen him wear the same shirt "like 600 times."
In Tears Are Not Enough (2), when Mr Simpson told his Grade 9 homeroom class that Craig's father Albert Manning had been killed in a car crash over the weekend, Marco asked him if Craig was alright. Mr Simpson assured him that he was fine. Like everyone else, Marco was shocked when Craig came to school that day. He said to Jimmy that he was amazed that he was taking his father's death so well. When Craig told them that he got an A in his science test, Marco and Jimmy congratulated him. Craig attributed to his father's help, referring to him as a good study partner. They then expressed their condolences and Marco asked him if he was okay. After Craig made a joke about his father's death, they were both concerned.
When Jimmy and Spinner started arguing about which of them would be voted luau king and queen, Marco told them to do it later. After Spinner left, Marco said, "Okay Jimmy, give it up. He and Paige would make an amazing luau king and queen."
In Pride (2), Jimmy finds Marco being jumped by a bunch of guys for being gay. He then comes to his rescue. When Marco is in tears, they share a hug.
In Against All Odds, Spinner, Jimmy, and Marco are hanging out at Jimmy's house. When Spinner suspects that Marco has a crush on him, Jimmy comes to his defense.
In Accidents Will Happen (1), Jimmy mentioned that Marco was tutoring him in Algebra.
In Back In Black, Marco was extremely upset that Jimmy had been shot. During a group counselling session with Ms. Suavé, he said, "I am shaken. I want to turn back time. I need...I need to believe that life's better than this."
Before Downtown Sasquatch's recording session in Neutron Dance, Marco sadly told Craig that they would sound better if Jimmy could play with them. Craig said, "I wish he could too."
After Jimmy was shot, Marco and Craig were especially supportive of Jimmy during his recovery. In Secret (2), Jimmy was anxious to return home after being in hospital for several months and was looking forward to seeing a Kid Elrick concert with Craig and Marco. However, his father Jermaine Brooks told him that the house would not be ready for another week and that he would have to stay in hospital for the time being. Not willing to accept this, Jimmy convinced Craig and Marco to break him out of the hospital the next day so that they could go and see the concert together. Jimmy and Marco wore black hoodies for their escape while Craig entered the hospital wearing a fedora and trenchcoat. Craig distracted the nurse on duty by continually asking for a fictional German doctor and then pretended to be extremely ill. When the nurse left to get him help, he, Jimmy and Marco made their escape.
While it was difficult for Jimmy to navigate his way around the club where Kid Elrick was performing, he did extremely well and he and his two friends were in the front row for the entire concert. As Craig and Marco sneaked Jimmy back into the hospital that night, they excitedly discussed the concert. When Craig commented that they were so close to Kid Elrick that he was practically sweating on them, Marco said, "I am never gonna shower." A confused Craig laughed at his best friend's odd comment while Jimmy said that he would smell like Jack Daniel's if he did not wash. However, the three boys found Jimmy's father there waiting for him. Jimmy convinced him that he was ready to come home but that his father need to be ready. Mr Brooks agreed to collect Jimmy the next morning and bring him home.
In Eye of the Tiger, Marco was among the many students present to greet Jimmy at the front of Degrassi when he returned to school after three months in the hospital. The next day, after it became common knowledge that Spinner was responsible for dumping the paint on Rick, he and Craig confronted him. Craig told him to stay away from Jimmy while Marco told him that he was no longer invited to Jimmy's welcome back party at Craig's house. However, after getting drunk with Jay Hogart, Spinner showed up anyway. Craig angrily told him to leave. Spinner begged for forgiveness but Jimmy ignored him, telling Craig to continue playing karaoke as they had been doing before Spinner arrived. Spinner left but Marco saw that he took his keys with him and realised that he was going to try and kill himself. He and Craig attempted to stop Spinner from driving away but Jimmy moved himself in front of the car. He told Jimmy that he was not going to stop him as he was dead to him already. Craig then confiscated Spinner's keys.
In Venus (2), Jimmy, Marco and Craig had lunch together in the cafeteria.
In Weddings, Parties, Anything, Downtown Sasquatch were practicing a song. Marco and Jimmy are messing around so Craig stopped. He criticizes them and said they needed to get a gig at a wedding to buy recording gear to record their own album. Jimmy said that wedding bands were lame. They are all fighting and Ellie stopped them. Jimmy's father Jermaine Brooks came and drove both his son and Marco home.
In I Still Haven't Found What I'm Looking For, Marco and Craig were both disappointed that Jimmy was leaving the band to try out for a wheelchair basketball team but wished him look.
By Together Forever, Jimmy had rejoined the band but it broke up shortly afterwards when Craig moved to Vancouver to pursue his music career.
In I Against I, Marco convinced Jimmy to cut Spinner some slack after he dunked him into a basin of freezing water five times in a row and planned to do it another ten. Jimmy supported Marco's Safer Sex seminar. He told Marco that it was a bad idea to resume his friendship with Spinner.
In What's It Feel Like to Be a Ghost? (1), Jimmy attended the welcome home party that Marco and Ellie threw for Craig at their house.
In It's Tricky, Marco is seen at the club where Jimmy was performing.
- (Craig shows Jimmy and Marco his science exam in which he got an A+)
Jimmy: "A! That's my man."
Marco: "Wow. That's amazing, buddy."
Craig: "Yeah, my dad actually did something worthwhile for me. He was a good study partner."
Jimmy: "Look we're really sorry to hear about your dad, man."
Marco: "Yeah. So you okay?"
Craig: "Guys, I'm fine. Hey, I'm the lucky one. My dad died. I, I walked away with a scratch."
Marco: "I thought you weren't in the car..."
Craig: "Friday night, we're like speeding down the highway, my dad's mad and he won't slow down. Ahead there's a rig. I see it, my dad doesn't and we hit...hard."
(Jimmy and Marco are shocked. Craig laughs)
Craig: "Guys, I was at Joey's when it happened! I had you going though." - Tears Are Not Enough (2)
- Jimmy: (to Marco) "It's okay. It's okay, I'm here. I'm here and not going anywhere, okay?" - Pride (2)
- They were both good friends with Spinner Mason, Paige Michalchuk, Ellie Nash and Craig Manning.
- Jimmy was the first straight male to show Marco kindness after he came out, as he had no issue with him being gay.
- Jimmy supported Marco after he was gay-bashed while Marco was very supportive of Jimmy after he was shot.
- They were both big fans of Kid Elrick.
- They were both founding members of Downtown Sasquatch.
- Neither of them had any siblings.
- They were both originally members of the Class of 2006. While Marco graduated with that class in High Fidelity (2), Jimmy was held back and graduated as part of the Class of 2007 in We Built This City.
- Craig included a song ("Kissing in the Stairwell") about Marco on his album Of Two Minds while he thanked Jimmy in its acknowledgements.
- They both attended J.T. Yorke's memorial service at Degrassi in The Bitterest Pill.
- They were both members of Archie Simpson's Grade 9 homeroom class 9F from 2002 to 2003.
- Like Jimmy's ex-girlfriend Ashley Kerwin, Marco served as Student Council President.