[Development Chronicle] Making AI your 'best subordinate'! A story of how I rapidly built a VRM x AI English conversation app using Google Antigravity and Gemini

This article is a long-form documentary that packs everything from [Chapter 1] to [Conclusion], including my realistic struggle of developing an app with AI, and my thoughts on future 'information literacy' and 'regional education'.It is a long-form documentary that includes everything from [Chapter 1] to [Conclusion]. I plan to update it in order on Tuesdays and Fridays when I have time.

It is a bit voluminous, but I would be happy if you could read it slowly at your leisure while having a cup of coffee.

📖 Table of Contents (Roadmap) of this article

[Introduction] The 'AI English Conversation App' I made and what I want to convey in this article

First, please take a look at this screen.

This is an English conversation web app called 'Shabetto' that I recently made. Just by opening the browser, a cute 3D avatar (VRM) will talk to you in natural English in real-time while reacting right in front of you.

It is a system where the user themselves enters their own API key (Gemini API) to use it, and the avatar's appearance and personality can also be customized to your liking. Since it is equipped with the latest Gemini Live API, it features the ability to have a natural back-and-forth conversation, like talking to a human, such as interrupting or nodding along.

I usually work as an IT instructor in Beppu City, Oita Prefecture. I originally worked for a company in Tokyo, but I got a little tired of the busyness of the city and moved to this region in my 30s. Currently, while running web development and programming classes and teaching at a vocational school, I am making it my life's work to 'eliminate the regional experience gap' by sharing AI utilization and the latest technology experience sessions.

As for this 'Shabetto' that I made... actually, I didn't type on the keyboard and write difficult programming code from scratch myself.

I said 'I want to make an app like this!' to the latest AI (Google Antigravity and Gemini) in Japanese, had the AI agent write the code, and when an error occurred, I gave instructions like 'fix this!'... it is a work that I created while consulting with what was like a 'super-talented AI subordinate'.

In this article, I will not explain difficult source code. Instead, I will talk openly about the realistic experience of how an ordinary IT instructor managed AI, what kind of failures they had, and how they completed the app, which is a real-life story.

I hope this will be a story of struggle that can encourage those who think, 'I want to make something using AI, but it seems difficult...'

So first, why did I decide to 'build my own English conversation app' in the first place? I will start by talking about that trigger.

[Chapter 1] The trigger was the trouble in English class. 'Existing AI apps are too expensive & have too little freedom problem'

[Chapter 2] A shocking original experience. The story of how I asked AI to 'make a blog' and it was completed in 4 hours

[Chapter 3] On to the main development! Forming the strongest AI expert team with 'SKILL.md'

[Chapter 4] Management techniques to make Antigravity your 'best subordinate' (Allow hell and spinning your wheels)

[Chapter 5] The Commitment to 'Zero-Cost Operation' and 'Information Literacy' to Protect Yourself

[Conclusion] AI Transforms 'Teaching' into 'Guiding'

[Complete Guide] VRM Avatar x AI English Conversation App 'Shabetto'

Thank you for reading until the end! I would be very happy if you could feel free to leave a like or a comment.