Well, kind of.
Mito has decided to hold an open tryout for players on the top team next year. Although meant for former pro players, semi-pro players, current school team players, and perhaps pro futsal players, anyone can submit the form to join the tryout if paying the 10,000 yen application fee.
On December 8, thhe first leg takes place with a day long exhibition, and players who do well will be asked back for an in depth look the next day.
I know I have basically zero chance of making the team, but I've played around as a goalkeeper recently and have a tiny bit of skill there. More for the fun of it, I think I might join the tryout. If nothing else, it should be a good experience and I think it's the kind of thing I'd always regret not doing.