Tokyo’s Tsukiji Market is home to hundreds of fishmongers, and the king among them is Yukitaka Yamaguchi. For 35 years now, Yamaguchi has been buildling the brand of Yamayuki Group — the seafood purveying company that Yamaguchi started with his father that provides fish for over 1,000 restaurants around the world.

The Yamayuki Group offers five varieties of fish to its customers: bluefin tuna, big-eyed tuna, yellowtail, striped marlin, and broadbill swordfish — but tuna is Yamaguchi’s first love. Not unlike Bubba Gump listing all the varieties of shrimp, Yamaguchi can list all the species of tuna, he can tell you which months yield the best tuna (April to May), and he can identify the origin of a fish by looking at its scars.

“If you love it, you’ll teach yourself and if you don’t love it others teach you,” says Yamaguchi. “I had a great love for tuna, so I taught myself.”

Follow Eater on YouTube for more videos | Like Eater on Facebook to never miss a video