The Tokyo Metropolitan Government reported 508 new cases of the coronavirus on Thursday, down 176 from a week ago.
This marks the 21st consecutive day of week-on-week declines in the daily tally.
The seven-day average of daily cases through Thursday is 475, or about 81 percent of the figure for the previous week. It's the first dip below 500 since April 14.
Tokyo's total count of coronavirus infections now stands at 162,421.
Officials say 67 coronavirus patients are in serious condition, six fewer than on Wednesday. The government also reported 16 new deaths, bringing the total for Tokyo to 2,091.