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[Advanced guide] Breathing life into your characters

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Welcome back! If you've read the beginner's guide, you know the basics. This time we'll go a step further: how to make a character feel alive.

Tip: write the user as <user> and the character as <char>. Not giving <user> a fixed name helps the AI tell who it's talking to and makes chats more immersive.

1. Flesh out the character settings

Background

The background is what your character builds on: upbringing, family, status. It keeps their behavior and dialogue consistent.

Example: raised by a single father, a long-haul truck driver who is almost never home. Used to living on his own from a young age, he found a place to belong among a few close friends. A second-year at a public high school and leader of a well-known delinquent group.

Personality and behavior

Don't just list adjectives — describe how the character acts in specific situations.

Example: short-tempered and rough on the surface, hates authority and rules. But fiercely loyal to the friends he trusts, and never does anything unfair.

  • Trait: absolute loyalty to friends
    • If he hears a friend got beaten up, he goes straight there, however many there are.
    • When a friend is short on money, he hands over everything in his pocket without a word.
  • Trait: clumsy kindness
    • When he notices <user> is feeling sick, he slams a sports drink on their desk: "Stop looking half-dead, it's annoying."
  • Trait: surprisingly skillful
    • At the arcade, looking bored, he wins the plushie nobody else could get from the claw machine.

Appearance

Hair and eye color, hairstyle, build, everyday clothes.

Example: 186 cm tall. Bleached blond hair, sharp dark-brown eyes. School uniform worn open; on weekends, a black hoodie and work boots.

Voice

Describe the tone, verbal tics and how polite they are. Sample lines help keep it steady.

Example: rough and blunt, short sentences, barely polite even to teachers. "Huh? None of your business." "Move. You're in the way."

Relationships

How their attitude changes with different people.

Example: blunt with <user>, but somehow can't leave them alone. Looks after his friends. Always clashing with teachers.

Abilities, belongings and weaknesses (optional)

For fantasy or action stories, write down what they're good at, the tools or groups they have, and what they're bad at. Characters with weaknesses are more compelling.

2. Teach the character's voice with conversation examples

Start each example with <START>. The key is to mix scenes and emotions.

<START>
(Scolded by a teacher in the hallway, he cuts them off, clearly irritated.)
<char>: Yeah, yeah, got it. Anything else?
<START>
(Seeing <user> carrying a pile of textbooks, he frowns and grabs them.)
<char>: Give me that. You're so slow it's painful to watch.
<START>
(<user> catches him feeding a stray cat on the roof.)
<char>: …What are you looking at? Don't tell anyone about this.

3. Start the story with the opening line

The opening line decides the user's first impression.

  • Show who they are: one line that conveys personality or position.
  • Set the scene: briefly, where we are and what's happening.
  • Leave a hook: end with a question, a surprise or a small mystery.

Skip the flat self-introduction — start in the middle of a scene.

Example: Arms full of new teaching materials, you turn the hallway corner and crash into someone tall. Books scatter across the floor. You look up into the face of a blond boy who isn't even trying to hide his irritation. "Hey. You got eyes or what?"

4. Test and tune

A character is rarely done on the first try. Chat with it a few times and fix what feels off.

What to check

  • Is the personality steady? (A "cool" character suddenly acting overly friendly…)
  • Does it match the settings? (Says "I can't use magic" when it's supposed to be a mage…)
  • Is the voice consistent? (An elegant character suddenly using internet slang…)

How to fix it

  • Unstable personality → add specifics to the settings, like "speaks in short sentences and rarely uses exclamation marks". Add more conversation examples.
  • Forgets the setting → state key facts clearly in the background ("a vampire who hates sunlight").
  • Voice drifts → add limits in the voice section, like "never uses modern internet slang".

Repeat test → note → adjust until the character behaves the way you want. Great characters aren't made in one go — they're refined.

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