Seijin

It was Seijin no hi.  That's the day that anyone who turns twenty that year celebrates being officially recognized as an adult.  Usually after the ceremony there is drinking (now legally of course) and probably karaoke.

This year looks like they've forgone that for Arukismaho = walking whilst using a smartphone.  Many ceremonies were cancelled or held on-line.  Chigasaki decided to hold one IRL.