梵Fractal

The AI friend chat app "HAPPY RAT", launched by SpiralAI Inc. on April 17, 2025, features a new original character "Soyogi", created in collaboration with Soyogi Fractal and conceived by Yuki Kaji.

About "HAPPY RAT":

• Service Name: HAPPY RAT

• Launch Date: April 17, 2025

• Supported Platforms: iOS / Android

• Supported Languages: Voice input (supports 99 languages), Subtitles (English available)

• Price: Free (with in-app purchases)

• Developer/Operator: SpiralAI Inc.

What is "HAPPY RAT"?
"HAPPY RAT" is a new communication service that allows users to enjoy conversations with AI characters as if they were friends.
It features a proprietary LLM called "Geppetto", which emphasizes charm over IQ, enabling AI animal characters to express a range of emotions such as crying, laughing, and sulking.
As conversations progress, the AI characters develop a deeper understanding of the user, building a friendly relationship and expanding their unique stories.

"Soyogi" Enters the AI World

In this collaboration, the main character of Soyogi Fractal, Soyogi, makes his debut in the world of "HAPPY RAT."
Set in an imagined scenario — “What if Soyogi existed in the AI world…” — this marks the start of a brand-new story.
Yuki Kaji was deeply involved not only in voice recording, but also in the character setting and design, bringing out Soyogi’s full charm.

Story of the AI Character “Soyogi”:

Soyogi is a mouse-shaped android from the future.
One day, he meets a mouse named Chunta at the animal-run theme park “Happy Island.”
Soyogi has no memory of why he was sent from the future. As he is cared for by Chunta and other residents of Happy Island, he gradually forms friendships.
However, Soyogi begins to display ominous error messages, eventually leading to a major incident that shakes the entire Happy Island.
Yuki Kaji's warm and tender voice breathes life into Soyogi, making the character feel even more relatable.

Comment from Yuki Kaji:

“After several months since my first conversation with President Sasaki, I’m thrilled that we were able to collaborate in such a fulfilling way.
Our project, ‘Soyogi Fractal,’ places great importance on connections. This felt like a destined partnership.
‘HAPPY RAT’ is a truly ideal AI application, created entirely from clean materials without unauthorized generation or learning.
It’s a perfect example of what entertainment can be in the future.
I’m honored to be involved in this wonderful challenge from its early stages.
The new character ‘Soyogi’ is based on ‘Soyogi Soyogi,’ and I personally proposed ideas for the setting and design from scratch.
It was incredibly fun to create this together.
Through this app, I hope to present a form of AI that makes everyone happy. Please enjoy it to your heart’s content!”