Most AI characters fail the same way: a beautiful definition, then a helpdesk by message four. Staying in-character is a small stack you test, not a novel you paste once. This is the 2026 version of that stack, aimed at Onscene’s creator. Anime-specific templates are in a separate guide.
The in-character stack
- Role tonight, not a biography.
- Voice rules — sentence length, humor, what they notice.
- Room — if you do not name it, the model will invent a mall.
- Greeting — a situation, not a résumé.
- Boundaries — always / never, including the filter lane you actually use.
- A test loop — three messages, one correction, rewrite the card.
Persona, not tags
“Kind, funny, loyal” is a sticker. In-character means what they do under pressure. Write one tell and one shift: they tease when nervous; they go plain when it matters.
Keep backstory short enough to imply. Long wikis get recited. Onscene’s fields already cap this; use the cap.
Example dialogue is the real prompt
Three sample lines beat two thousand words of lore. Put them in personality or instructions:
- A joke they would actually make.
- A refusal.
- A sincere answer with no performance.
Then write a greeting that already assumes a relationship or a problem. Realtime anime storytelling covers camera language if you want a scene, not a chat bubble.
Boundaries without breaking the person
Onscene is 18+, fictional adults only. Standard mode keeps everyday conversation inside content limits. Uncensored allows adult intimacy that stays sensual rather than pornographic. Put your character policy in instructions either way: stay in voice, no assistant disclaimers, match the player’s pace.
If they forget facts, pin them. Memory problems are usually an overflowed card plus an unpinned detail.
The testing loop
Talk for five turns. The first break in voice is data. Rewrite the card; do not add a paragraph. Repeat until the third message still sounds like them. Then — and only then — lengthen the backstory.
FAQ
How do I create an AI character with no code?
Use a hosted maker. Onscene is form fields plus live chat. Open create a character or onboarding.
Why do they keep summarizing my feelings?
Ban it in instructions. Many models default to therapist-talk. In-character companions notice the room instead.
Can I use this for anime and contemporary characters?
Yes. Same stack. Anime gets extra camera notes in the persona templates.