[Free, Part 2] How to Create AI LINE Stickers | Tools to Use and Preparation to Start for Free [2026 Edition]
This series (10 parts in total) is a practical guide to starting a side hustle creating LINE stickers using AI, from scratch until you sell your first set.
In Part 1, I introduced the financial mechanics of selling LINE stickers and the points to keep in mind when using AI.
In this second part, we will finally move on to "choosing tools" and "preparation" before starting production.
The goals for this session are the following three:
Decide on one image generation AI to use
Prepare to start using LINE Creators Market
Create one initial character concept
Once you have finished this, you can start creating the actual sticker images from the next session.
1. Which image generation AI should you choose?
When you search for "AI LINE stickers," many services appear, such as ChatGPT, Gemini, and Midjourney.
There are so many options that it is not uncommon for people to get stuck at the very first step.
However, you do not need to compare everything from the start. First, you want to check these three points:
Is it easy to increase the number of expressions and poses for the same character?
Is it easy to give correction instructions in Japanese?
Are the terms of use suitable for you to use for sales?
It is important not to choose based solely on high image quality, but to look at whether it is easy to create stickers as a set.
2. The most important point is "character consistency"
LINE stickers are sold by gathering multiple images of the same character with different expressions and poses.
Even if you can make one cute image, if the face, body shape, color, or clothing changes in the next image, it won't look like a single set.
When testing tools, try checking them as follows:
Using the same character, can you create three patterns—'smiling,' 'surprised,' and 'thank you'—and have them still look like the same character?
Just by doing this test, you will understand quite well how compatible the tool is for sticker production.
To improve consistency, it is also important to be able to use reference images, make partial corrections through conversation, and easily reuse the same prompts.
3. Features of Major Image Generation AIs [2026 Edition]
Gemini Image Generation (Nano Banana series)
It is easy to use from a Google account, and you can generate or edit images in a conversational format.
Google's official help states that 'Nano Banana 2' can be used in Gemini Apps, and 'Nano Banana Pro' is also provided to paid users. The models and usage limits available may vary depending on the region, account, and plan.
Because it is easy to try editing parts of an image or creating different expressions while keeping the original atmosphere, it is also suitable for creating character variations.
ChatGPT Image Generation
Its strength lies in the ease of making corrections while continuing the conversation, such as saying 'make it look a bit sleepier' or 'don't change the body color.'
If you are already using ChatGPT, you can proceed with text creation, character setting, dialogue ideas, and image generation all within the same conversation.
According to OpenAI's terms of use, to the extent permitted by law, the rights to the input remain with the user, and the user owns the output. However, it is the user's responsibility to check the output, ensure it does not infringe on third-party rights, and comply with various policies.
Midjourney
It is strong at creating atmospheric illustrations and world-building, making it attractive if you want to prioritize the visual appeal of the work.
On the other hand, to strictly match faces and body shapes for stickers, adjustments using reference images or parameters may be necessary. For your first set, it is better to allow some time for learning.
Adobe Firefly, Ideogram, etc.
Firefly has features like integration with Adobe products, while Ideogram excels at text expression within images; each has its own characteristics.
However, features and terms of use are subject to updates. 'Paid' does not necessarily mean you can sell, and 'free' does not necessarily mean you cannot sell. Once you have decided on a service, check the official terms at the time of generation.
Conclusion for Beginners
If you are unsure, it is recommended to start with a service you already use regularly.
If you use Google services often → Gemini
If you use ChatGPT often → ChatGPT
If you want to create a detailed world for your art → Consider Midjourney as well
Rather than searching for the perfect tool from the start, choosing one and creating three images of the same character to compare will help you move forward faster.
4. Differences Between Free and Paid Plans [Do Not Judge by Price Alone]
Image generation AI services have both free tiers and paid plans.
Here, you should be careful about the following assumption:
"It is not universally decided that 'free plans are not for commercial use, while paid plans are.'"
The conditions for commercial use vary depending on the service's terms of service, account type, features used, and the time of generation.
While some services allow commercial use even on free plans, having a paid plan does not permit the infringement of third-party rights or prohibited uses.
Main Features of Free Plans
There are limits on the number of generations and available models
Wait times may occur during peak usage
Suitable for testing character concepts and usability
Commercial use conditions must be checked individually in the service's terms
Main Features of Paid Plans
The number of generations and options for high-performance models may increase
Easier to mass-produce variations and make revisions
High resolution, priority processing, and additional editing may be available
Paying does not automatically resolve copyright or trademark issues
Pre-sale Checklist
Check the official terms of service for the service used for generation
Check the conditions regarding commercial use, sale, and redistribution
Check that it does not resemble famous characters or works
Save the model used, generation date, prompt, and editing history
Accurately declare the use of AI to LINE
If you are unsure, we recommend creating character drafts for free and re-checking the terms of use before creating the final images for production.
5. Preparation to Start LINE Creators Market
In parallel with the image generation tool, start preparing the place where you will sell your work.
At LINE Creators Market, you sell through the process of creator registration, registration of work information and images, review, and release.
Things to Prepare
LINE account
Email address to use for registration
Name, address, phone number, etc., to be registered as creator information
Payment-related information to receive distributions
Basic Registration Flow
Log in with your LINE account
Check the terms of service
Enter the required creator information
Follow the instructions to complete registration
Confirm that you can log in to your My Page
Since screens and verification methods may change, please follow the official instructions displayed.
If you are a minor, you must obtain the consent of a legal representative, such as a parent or guardian, before using the service.
Once registration is complete, the next step is to prepare the sticker title, description, and images, and then apply for review.
6. How to create your first character concept
Once you have prepared your tools and sales platform, decide on your main character.
Think about 'who will use it and when'
Whether it sells or not is not determined solely by how well you draw.
It is important that it is easy to use in daily conversations and that emotions are conveyed immediately.
A slightly polite cat that can be sent to colleagues
A gentle bear that can be used by families raising children
A sleepy bird that speaks for the feelings of tired office workers
A high-energy rabbit that can be sent to fellow fans
By deciding not just the 'motif' but also who will use it and in what situations, the necessary phrases will become clear.
Create a character setting sheet
Try filling in the following 5 items.
Motif: Round cat, lop-eared rabbit, etc.
Name: A name that is easy to remember and easy to call
Personality: Laid-back, slightly sharp-tongued, always looks sleepy, etc.
Tone of voice: Polite language, mostly hiragana, short replies, etc.
Appearance: Body color, eye shape, cheeks, clothes, accessories, etc.
This setting sheet will become the 'consistent axis' when you increase the number of images.
3 Tips for Maintaining Consistency
Save the basic prompt for the character
Use the same instructions for face, body shape, color, and clothing every time
Only swap out the expression, pose, and dialogue
If possible, save the reference image you created first and use it as a reference image for the next generation.
Template for Character Generation Prompts
An original character of a cream-colored kitten with a round and soft impression. Cheeks are light pink. Eyes are half-closed and look a bit sleepy. Simple lines and gentle pastel colors. Plain white background. The whole body is within the frame with plenty of margin around it. Expression is <big smile>, pose is <hands clasped in front of chest>. For chat stickers. Do not resemble existing works or characters.
Alternatively, you can create just the character first without putting text directly into the image. If you add the text later using editing software, it is easier to correct typos and you can unify the font for the entire set.
7. Today's Action
To ensure you don't just read this and finish, I've narrowed down what to do today to 3 things.
Decide on one image generation AI to use
Register for LINE Creators Market and check your My Page
Fill in the 5 items on the character setting sheet
If you have time, try creating 3 images with the same character—'smiling,' 'surprised,' and 'thank you'—and compare their consistency.
Summary
When choosing tools, look not only at image quality but also at character consistency.
If you are unsure, try starting with Gemini or ChatGPT, which you already use.
Do not judge whether commercial use is allowed based solely on whether it is free or paid; check the official terms individually.
Complete your registration for LINE Creators Market and your character settings first.
Save your base prompt and reference image, then change only the expressions and poses.
The preparation may seem mundane, but the settings you decide here will be effective when you create the next 8 or 16 stickers.
You don't need to aim for a perfect character from the start.
First, decide on one, create three, and compare them. Let's improve from there.
Next Episode Preview | Part 3
AI LINE Sticker Creation [Practical Edition] | From creating images to final touches before review
Next time, I will explain the following:
How to create variations of the same character's expressions
Sticker image size, format, and background transparency
Tips for placing text so it is easy to read
Checkpoints before submitting for review
Follow this series and let's complete your first set together.
*This article is based on information confirmed as of July 18, 2026. Tool names, pricing, usage limits, terms of service, and LINE Creators Market procedures are subject to change. Always check the official information for each service before generating, paying, or selling.
Reference (Official)