Confirmation of the first infection in Japan involving the new omicron COVID-19 variant on Tuesday has rekindled anxiety among companies over the risk of an economic downturn, with the threat of restrictions looming over the business environment once again.

Koichiro Sakaue, 51, a director at agricultural production company Sakaue in Kagoshima Prefecture, said his farm has already been suffering a labor shortage due to existing border restrictions.

"If they become even stricter, technical trainees from Vietnam won't be able to enter Japan again," he said.