Turn your original character into an AI character

Updated October 18, 2026

Many people come to Shiro with a character they already love: an OC from their writing, a tabletop RPG character, a mascot from their art, or someone they've been daydreaming about for years. Turning them into an AI character lets you talk to them, put them in new situations and see how they react. Here's how to translate what you know about your OC into a character that plays them well.

Start from what makes them recognizable

You probably know far more about your OC than will fit in a personality field, and that's fine. The AI needs the parts that show up in every conversation: how they act, how they speak and what drives them. Ask yourself: if a friend met my character for five minutes, what would they notice? That's what goes first.

Their two or three strongest traits, including the contradiction that makes them interesting.
How they talk: vocabulary, rhythm, accent written as word choice, catchphrases.
What they want right now, and what they're afraid of.
How they behave toward strangers versus people they trust.

Summarize the backstory

A ten-page history won't help much: the AI works best with a compact summary of what matters. Write the backstory in a few sentences, focusing on events that still affect how the character behaves today. "She grew up in the palace kitchens and still can't sit still while someone else cooks" is more useful than a detailed account of her childhood.

Leave out spoilers you want to discover through roleplay, or keep them vague. The character will happily hint at a mysterious past if you tell them they have one.

Decide who you are to them

When you chat, who are you? Your OC might be talking to a stranger, to another character from your world, or to you as yourself. Write this into the personality ("She has just met you at the border crossing and doesn't trust outsiders") or set up a persona for the character you'll play. Clear roles make the first scenes much smoother.

Bring their world with them

If your OC lives in an original world, include the essentials: the setting's name, the one or two rules that matter (magic costs memories, the city is underwater, gods are real and petty), and the names of people they'd mention. Keep it brief. A few anchoring details let the AI improvise consistently without you writing a whole encyclopedia.

Write a greeting in their voice

The greeting is your OC's first impression and teaches the AI how they write. Put them in a scene that shows them at their most recognizable: the grumpy mechanic elbow-deep in an engine, the knight practicing a speech they'll never deliver. See how to write a character greeting for more.

Looks and portrait

Write a short physical description: hair, eyes, build, clothes, anything distinctive. It's used to generate a portrait and helps the character describe themselves consistently. If you have your own art of your OC, you can upload it as the portrait instead (as long as you made it or have the right to use it). Generated portraits come in several art styles; see making a great character portrait.

Keep them private or share them

Your character can stay private, so only you can chat with them. You can also share them with friends, with chosen friends, or publicly on Discover. If your OC is personal, there's no need to make them public; if you'd like others to meet them, read sharing your characters.

Tune them through conversation

Chat for a while and notice where the AI drifts from how you imagine them. Maybe they're too polite, too wordy or too quick to trust. Add a direct sentence to the personality to correct it: "He never apologizes", "She answers in one or two sentences", "They distrust anyone who flatters them". Small, specific changes work better than rewriting everything.

Use pinned memories in a chat for facts that must never change in that story, such as their sister's name or an old injury. More in how memory works.

Give them a voice

If you've always imagined how your OC sounds, pick a voice for them in the character's Voice section and listen to samples until one fits. Then you can call them and hear them answer. See voice calls and character voices.

A note on fan characters

This guide is about original characters. If your character is based on someone from an existing series, keep it as fan fiction and follow our community guidelines. Never create characters that impersonate real private people.

Open Shiro