If you've ever bought supermarket sushi, you may know the taste trauma that hit Kazuhiro Shimura one night. But "disappointing" tuna sparked an idea: he'd develop an artificial intelligence (AI) system to make sure your sashimi is always delicious.

Shimura, a director at advertising firm Dentsu Group's Future Creative Center, came up with the concept for Tuna Scope AI as he chewed his raw dish while watching a television show on fish merchants who spend a decade mastering the skill of selecting high-quality tuna for sushi restaurants.

Using a deep learning algorithm to crunch through grading data from merchants, Tuna Scope has now evolved into a smartphone app. Clients can download and use it anywhere, creating "a unified grading standard" for an industry that relies on local know-how, said Shimura, who is working with Japanese trading company Sojitz Corp. to promote his technology.