Illness has forced the closure of Flinders Lane omakase restaurant Kappo from June 9.

The Japanese fine diner, which has a hat in the current Good Food Guide, is built around the skills of chef Kentaro Usami.

But with Usami largely out of action at present, co-owner Simon Denton says they've decided to switch gears.

Next week he'll announce new plans for the site, hinting it will be "something warming" for winter.

Denton opened Kappo with Miyuki Nakahara and Takashi Omi in 2014.

But over the past 17 years he has become adept at transforming the site, on the corner of Flinders Lane and Spring Street.

He launched modern Australian fine-diner Verge there in April 2001 and reopened it in 2012 as a udon noodle operation, Nama Nama.