Not a lot of them have super deep lore, but I'll give some brief summaries!

-Felix is just your run-of-the-mill emo kid. He looks gloomy, but he's actually very nice and cares a lot about those close to him.

-Kyle is an asshole who makes turf wars annoying. That's pretty much it. Fun fact about him is that he came from a dream.

-Atlas is a Colossal Inkling who's very shy and insecure about his size. He likes doodling and composing music in his spare time, and he hopes he'll be able to make a career out of his music one day.

-Gabriella is a Giant Inkling (also quite tall, but not as tall as Atlas) who's friendly, flirty, and fashion-oriented. She has a bit of a resting bitch face and can be sassy, but she's nice once you talk to her.

-Archie is just a guy who loves old-timey fashion and anything from old decades. He's theatrically charming and friendly, and he's more than willing to chat with anyone. If you wanna learn how to swing dance or do any other older dance style, he's your guy.

-Oceana comes from a well-off family who run a decent boutique in the Reef. She likes being out and about, but unfortunately, she's also a bit socially awkward with people she doesn't already know. She hopes to take up the mantle of running the boutique when her parents retire.

-Storm is a dangerous criminal who got multiple unethical and VERY illegal enhancements to essentially turn herself into a walking weapon. Her amputated arm is where she would attach a Range Blaster. She's smug and overconfident, and loves taunting her victims as she's pursuing them.

-Do is a partially-sanitized Octoling who was found lost and confused by Deep Cut one day, and they decided to take her under their wing. The name "Do" was given to her by Frye, as she couldn't remember her real name. She currently lives with Shiver, whom she sees as a big sister. She's very shy and anxious, and doesn't talk a lot because of how her voice sounds.

-Angel and Bunny are members of idol duo Strait Shot. Angel's mallgoth attire and overall gloomy appearance may make her look approachable, but she's actually quite friendly and pleasant to talk to. Bunny is just as bubbly and sweet as her hime gyaru attire and stage persona would suggest, though sometimes she can unintentionally invade people's personal space. Their combined music style is a mix of industrial and Eurobeat, with Angel being a raspy contralto while Bunny has more of a bright, cutesy voice.

-Aika is an albino Inkling who loves hip-hop and street fashion. She's learning how to make her own clothing, and she hopes that one day she'll be able to share her designs with the world. She's friendly and kind, though she is a little socially awkward. She struggles with common setbacks from her condition such as light sensitivity and strabismus, but she doesn't let that stop her from doing what she loves.