Hiroshi Yoshida is facing a dilemma.

Under an anti-smoking ordinance adopted by the Tokyo Metropolitan Assembly last month, the 73-year-old owner of a small udon (wheat noodles) restaurant in the Takadanobaba district will soon have to make a choice: declare the entire interior nonsmoking or install a strictly ventilated room for smokers where no drinking or eating will be permitted.

Adopting a nonsmoking policy would be a huge turn-off for some of his regular customers. But setting up a ventilation system would require sacrificing a good portion of what little dining space he has left. Kazunoya, Yoshida's decades-old establishment in a narrow alley near Takadanobaba Station, can accommodate just over 10 customers at a time.