Applications for the new subsidy for families with children enrolled in Tokyo private junior high schools are now being accepted as of 1 September (until 30 September).
If you have a child enrolled in a private junior high school in Tokyo and meet the household income threshold (which doesn’t seem as restrictive as other subsidies I’ve seen), you might be eligible for a subsidy of up to 100,000 yen per year toward your child’s tuition (first year paid in January 2024; applications required every year).
According to the information on the website, your child’s private JHS should be contacting the parents/guardians with information on how to to apply, but if not, you can apply directly through the website (東京都私学財団).