A group of workers make fillets of katsuo (skipjack tuna) for katsuobushi, at the Takeuchi Ltd katsuobushi factory in Usa Town, Tosa, Kochi Prefecture, Japan, May 16, 2022. Katsuobushi (smoke-dried katsuo) is essential to Japanese cuisine, but the number of its manufacturers in Kochi has plunged in forty years from dozens to only a few. "I'm really unsure if we can continue this," said managing director Taichi Takeuchi, 36. REUTERS/Kim Kyung-Hoon SEARCH "KYUNG-HOON JAPAN SUSHI" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES