七五三/Shichi-go-san means 7-5-3.
It is held on November 15th every year
If you’re 7, 5 or 3 years old your parents will dress you up in traditional clothes and take you to a shrine to pray for your health and flourishing.
People often go to the shrines with their dolled up kids any time during November.
It’s a rite of passage for any Japanese child
Also doing family photoshoots is pretty common.
Check out uncovering Japan for a cool background of shichigosan.