[OOC][PLOT] The Third Thread of Planning for Arc 1 - Arrivals

[robkelk]

Spotted on Tuxedo Unmasked:

The year you enter school, and thus your age for any given school year, is determined by your age as of March 31 of the following year. We know that Mamoru’s birthday is August 3 and that he’s a second-year high school student, so he must be 16 at the start of the manga and turning 17. For a list of school years and ages, see Age by Academic Year

Which puts Tomo as the oldest of the Azumanga Daioh girls.