Some folks may not move in until the 臨時会 but I see some vans going in so I'm assuming some are.
It might sound intimidating, but just go to the 参議院議員会館, mark 挨拶 and 予約無し on the paper, and they'll let you in. It doesn't matter if you've never met them, hell it doesn't matter if they represent another prefecture. There's going to be a ton of people in the room, but find the secretaries and say 〇〇先生にお世話になりました and congratulate them. You don't have to wait to meet the Diet member themselves, but exchanging business cards and maintaining relations with the secretary(ies) is crucial if you want to advocate for something.
If you want to meet 衆議院 folks, go during 臨時会 and you can also stop by their buildings too. If you miss that window you're not going to see them until September. There are two 衆議院議員会館s but they'll let you in even if you're at the wrong one so don't worry.
If you're not in Tokyo, your new representatives (and maybe some of the 全国比例 folks too) will probably have a permanent 地元事務所 near you, so you can do the same there. I wanted to post on the main sub since there was a post on advocacy there, but am posting here instead because going to Nagatacho on a short notice isn't realistic for most people outside of Tokyo.
by RandomPerson0703