The Tokyo Metropolitan Government confirmed 439 new cases of the coronavirus in the capital on Thursday.
The figure is down 69 from a week ago, marking the 28th straight day of week-on-week declines.
The seven-day average of cases through Thursday is 391.7, or 82.4 percent of the figure for the previous week. It's the first time since April 6 that the seven-day average has fallen below 400.
The total number of confirmed infections in Tokyo now stands at 165,163.
Officials say 55 coronavirus patients are in serious condition, two fewer than on Wednesday. They also say six people who tested positive for the virus have died, bringing the total fatalities in Tokyo to 2,134.