As a country with a leading fishing and seafood industry, tuna is one of Japan’s national dishes. For years, the country has enjoyed a stable supply of high-quality tuna on account of merchants, or professional tuna inspection artisans, who have long determined the quality and price of a given fish by inspecting the cross section of its tail day in and day out. But today, as the master artisan population continues to age, this artisanal craft is said to be facing danger of disappearing.

We want to ensure that people all around the world, rest assured, can enjoy the same standard of delicious tuna, even into the future. This was what drove us to gather approximately 4,000 cross-sectional images of yellowfin tuna tails and use them to develop TUNA SCOPE - an AI system that mastered the inspection skill unassisted through deep learning to become the successor to the tuna artisans.

In March 2019, the beta version was implemented for the first time at a fish processing facility in Yaizu, one of Japan’s major landing ports. Limited servings of the tuna that the AI graded as highest quality eventually went on to be served to customers at Kantaro Tokyo, a conveyor belt sushi restaurant located in the underground shopping complex of Tokyo Station.

On the first day the AI Tuna was available on the menu, a massive line had formed outside the store before it had even opened. Posters and tapestries with the AI Tuna logo adorned the restaurant exterior, compelling many passers-by to stop out of curiosity. Little by little, the line continued to grow, and the first plate was served on March 27, and in just five days, all 1,000 plates of the AI Tuna sushi had sold out.

And what did the customers have to say?

A vast number of people left reviews with many commenting on the flavor, stating how it tasted different to the tuna they have had in the past and how it was extremely tasty with a fine texture. Others were curious about the development process and technology behind TUNA SCOPE with some even expressing their hopes for an AI Tuna of even higher quality and enthusiasm for the future that AI and technological advancements may bring.

From the 561 surveys that were filled out, it was revealed that 98% initially became interested in trying the tuna after hearing that it was AI endorsed, and 80% thought it tasted different to their usual tuna. Moreover, 88% of customers stated that they would be eager to try AI tuna of even higher quality, showing how many are interested in and in anticipation of the advancement of TUNA SCOPE.

Currently, we are still working on improving the accuracy and quality of TUNA SCOPE by conducting AI-based quality inspections day in and day out while the system continues to learn through intricate feature extractions of data on tuna tail cross sections. A future where this AI system, which has learnt from master Japanese artisans, goes beyond Japanese shores to become the global standard for measuring tuna quality around the world, may not be that far.

We are striving to create a world where everyone can enjoy the same standard of delicious tuna, and until that goal is met, our work on this project will continue.