Grace Monroe is the main protagonist of the fanfiction Train Chasers

Despite being the youngest, she prides herself on being the "de facto" leader of the friend group, and responsible for bringing everyone together to figure out the mystery of the train.

Her initial interest in the train may have been born of mostly boredom (and trying to stay out of her parents’ line of sight), but she becomes more invested in the case over time. Since picking up that notebook, she's been plagued with strange visions.

Ryan Akagi is a surrogative brother to Grace, sort of. Despite his inability to remain in one place himself, he helps keep Grace grounded. Ryan left town for a few years prior to the events of Train Chasers, but returns once more to Min-Gi with plans for a gig that will allow them to move on with their lives for good. However, Ryan is acting pretty shady about the gig. Perhaps there is more that Ryan is not letting on. He doesn't seem particularly interested in reopening the wounds of the past by investigating the mystery of the train, but he's willing to play along for now.

Jesse Cosay is the best friend of Lake and an overall friendly guy. Too friendly, perhaps. When a “man test” results in his little brother getting hurt, Jesse hides from his brother instead of standing up to his “friends” that pressured them. He is the first person who entered the train when looking for the maphe and Lake stole from their chaperones.

Mikayla Agyeman is a nerdy girl who always has a smile on her face and her nose buried into the computer. Her best friend Tulip may be the one thing she loves more than CSS and HTML. She and Tulip accidentally fell backwards into the train.

Amelia Hughes is the current conductor of the mysterious “numbers train”. She took over the train when she was in her late 20s and has been in charge ever since. Her fiance presumably died and in her grief has been trying to recreate her life with him before he died. She hasn’t been very successful.

Kez Lewis was Ryan and Min-Gi’s babysitter when they were younger. She is seemingly popular with many friends, but her friends do not seem to feel the same way.She disappears one night after a party and only returns years later, with a lot more baggage than she started with. She is the key to figuring out the train.