🇯🇵 Kazuki Nakata

The double is rare because the two disciplines pull training in opposite directions. Lead climbing rewards a high aerobic and anaerobic capacity in the forearms and the discipline to keep moving efficiently on a route that lasts several minutes; the decisive skill is pacing and the ability to recover on poor holds while still climbing. Boulder rewards maximum recruitment over a few seconds, explosive movement, and the analytical speed to decode an unfamiliar sequence in the minutes allowed. Training for one blunts the other, which is why national programmes normally choose a lane for an athlete by their mid-teens.

Arco is also the sport's most historic competition venue — the Rock Master site on Lake Garda — and the routesetting there is unforgiving. The championship ran from 18 to 25 July 2026 and drew the strongest youth fields in the world across three disciplines and two age bands, including national teams from Japan, South Korea, China, the United States and most of climbing Europe.

Japan's dominance of youth climbing is structural rather than accidental. The country's competitive gym network is the densest in the world, its domestic youth circuit is deep enough that qualifying for the national team is harder than medalling at some international events, and its senior World Cup teams have been built almost entirely from that pipeline for a decade. Winning a Japanese team place in the under-17 category is itself a significant filter; winning two world titles from inside it is a different order of result.

In the lead final Nakata took the under-17 men's title, one of four lead champions crowned that day alongside Arisa Hayashi of Japan, Anika Deubler of Austria and Chanjin Jung of South Korea. Two days later he added the boulder gold, in a session in which Amélie Kägi of Switzerland took the corresponding women's under-17 title. The competition's own reporting framed the second win explicitly as an addition to the first — the lead–boulder double being the story rather than either medal on its own.

The combined format matters for what comes next. Olympic sport climbing now runs a boulder-and-lead combined event, in which athletes are scored across both disciplines in a single competition. An athlete who can win world youth titles in each separately is, by construction, built for that format — and the pathway from youth worlds to senior World Cup climbing in Japan is short.

Nakata's birth date has not been published on a public federation or encyclopaedic profile, and the under-17 category tells you only that he was 16 or younger during the 2026 season. Nothing about his schooling, club or family is asserted here, because the published record on which this profile rests contains his results and little else.