Who's that hunk of blond beefcake crunching his abs on NHK's workout program "Minna de Kinniku Taiso"?

When the five-minute nightly exercise show launched for a four-episode run this August and attracted a huge cult following, social media users wanted to know the answer.

Tatsumasa Murasame probably wasn't the name they expected to hear. But then very little about the 30-year-old landscape gardener, bodybuilder and TV personality — born Jakob Sebastian Bjork in his native Sweden and a naturalized Japanese citizen since 2015 — conforms to people's ideas of who he should be.