The Tokyo Metropolitan Government says it confirmed 26,313 new cases of the coronavirus on Sunday.
The daily tally is down 5,228 from a week ago, and marks the second straight day of week-on-week declines.
The seven-day average stands at 31,732.7. That's 98.6 percent of the figure for the previous week.
This is the first time in about a month and a half that the average has fallen from the previous week.
Tokyo officials confirmed 12 deaths.
They said there were 36 seriously ill patients on ventilators or ECMO heart-lung machines, down one from Saturday.