Jamie is one of the residents, and local mailman of Beach City.
His work uniform consists of a light blue button up shirt with an envelope embroidered on both sleeves, a white shirt beneath it, cobalt blue shorts, a messenger satchel with an envelope embroidered on its flap, and a pith helmet. He also wears a pair of white socks under a pair of red shoes with white lining. He has a prominent nose, thick eyebrows, thick brown hair, and soft-black eyes.
When not working, he wears a casual outfit consisting of a black v-neck shirt and brown-green pants.
Jamie is easygoing, friendly, kind, and is (mostly) dedicated to his job. While he takes his duties seriously, his real dream is to be an actor. He considers himself a thespian, likes Shakespearean poetry, and has a flare for the dramatic (so much so that he and others refer to his bouts of overacting as being in "the drama zone"). He is very sensitive at times and does not take rejection well.
On one of his routes to the Crystal Temple, with the duty of dropping off a package for Emerald, he ended up running into Lapis Lazuli by the mailbox. He explained to Lapis the concept to his job, and how he usually stops by the Temple to deliver the mail, his added charm Lapis finding a bit interesting.
Overtime, he and Lapis begin to bond a bit more, hanging out together at a point during Halloween. He and Lapis went to see Zoltron, though quickly finding out it was more of a scam than anything.
Jamie stopped by the Crystal Temple during one of the routes after they returned from White Diamond's Space Station. He arrived with a present for Lapis Lazuli, unaware that she was currently fused with Jasper as Malachite. Garnet told him they were on a mission together and hadn't returned yet, misleading him in an attempt to avoid his life being "tainted" while Lapis was gone.
While not appearing physically much after this, he did try to invite Lapis Lazuli out for a dinner at the Crab Shack. It is unaware of his state during the Beach City Flooding incident.
Not long after building Sadie Miller's home, Steven found him with Lapis again, both this time working the delivery routes. They gave Steven a present in the form of a kitty clock.
His first major role was during the Season 6 finale: When White Diamond arrived in Beach City, he amongst many others had his memory wiped of all Gem and Pony related activity, but upon getting his memory back, he went with some others to get the Crystal Gems and Mane Six back. On this mission, he and his friends made it to Homeworld, though he became paralyzed with fear when confronted by one of the Robonoids. Upon escaping it, and upon reaching the palace, it was him who explained the situation to Yellow Diamond and Blue Diamond. When given the Sun Incinerator, Jamie had the ship turned to warp speed despite the risks involved, nearly making them all crash into the Space Station in process. Upon the arrival, and being confronted by Carnethysts, he stepped up when Lars Barriga was having trouble, taking the leader role. He made sure they were believable by telling them he was a leader since they were but pebbles, and giving an ominous warning that White Diamond was looking for new shards. It worked just enough to get them, him stating that all those months of acting practice had paid off.
He didn't get captured until after being found in Chamber 77, him being placed in the same holding cells as the others were. He began to question if there was something secretive in that chamber that White Diamond didn't want to make know of. This was confirmed when they contacted the Diamonds, them saying she didn't allow them inside there, which Jamie explained the details of said chamber, including the back cell marked "Facet-2 Cut-1X3". He managed to escape his cell with the other Humans, and aid in getting the others out before managing to make his escape with all of the group together.
He became the main protagonist within the Second Half of My Little Universe: Supernova "Fallout (Earth)", being the main perspective followed while Earth was under the Everstorm. He checked into the others throughout the ordeal, though he himself was scared and constantly leaving letters in the Harmony Gems mailbox to Lapis Lazuli.
To get his mind off of it for a bit, he went to Sour Cream RAVE, but during his time there he had a brief encounter with Adagio Dazzle. She attempts to seduce him out on the dance floor, but Jamie quickly reclined and decided to leave the party just before the party turned into a riot. He has a dream about Adagio Dazzle, and starts to worry if his love is turning away from Lapis and towards Adagio. He tried to handle it, asking some advice from Greg Universe about it, and checking in on the Pizza family after hearing of the riot in the R.A.V.E.. He starts to discover the possibility of Magic when he saw Jenny Pizza and Sour Cream fighting, and how they don't recall that same fight when they both stopped.
After figuring out the Dazzlings' involvement, Jamie joins Jenny, Sour Cream, and Buck in forming a band to fight against the Dazzlings, Jamie getting the idea of hiring Greg as their personal roadie. After the whole ordeal was taken care of, he became overjoyed when finding the Crystal Temple rejuvenating the Beach House, telling him the Everstorm was over.