The course for the race is incredibly unique. It's one of the only times people are allowed to RUN through Meiji Jingu (in Harajuku) and also down Omotesando blvd.
Map source (http://womensrun.jp/course/)
This year the race will take place on March 26, 2017. There is a 10km run for individual competitors that starts at 9:00am, and a family and kids run (1km) that starts at 9:30am.
This race is put on by sponsor "Puma". As a consolation for the usual tokyo style steep entry fees, you get a really beautiful race t-shirt, and your name (or nick name) on your race number.
For the kids and family packet, the price is reduced, so no fancy t-shirt, but definitely the enjoyment of running free, downtown!
This really IS a fantastic experience, second to perhaps only the Tokyo Marathon (if you care to exert yourself a bit less than the full 42.6km!) If you don't run, there's no reason not to pop downtown, enjoy the festive atmosphere and cheer on the participants.
This year the race T-shirts are pink! Happy running!