Is Tokyodoku free to play?

Yes. Tokyodoku runs in a browser at no cost, with nothing to install and no purchase to make.

How often does Tokyodoku reset?

Once a day. Everybody gets the same puzzle, and a new one replaces it when the game's day rolls over.

On tokyodoku.io, and you can play it inside this page without leaving Alldle.

It sits in Transport, alongside the other daily games of that kind in the catalogue.

Transport 2 plays

A daily puzzle where you place Tokyo Metro and Toei Subway stations into a 3x3 grid by matching each row and column clue.

Tokyodoku

Transport

Is Tokyodoku free to play?: Yes. Tokyodoku runs in a browser at no cost, with nothing to install and no purchase to make.
How often does Tokyodoku reset?: Once a day. Everybody gets the same puzzle, and a new one replaces it when the game's day rolls over.
What languages does Tokyodoku support?: Japanese.
Where does Tokyodoku run?: On tokyodoku.io, and you can play it inside this page without leaving Alldle.
What kind of game is Tokyodoku?: It sits in Transport, alongside the other daily games of that kind in the catalogue.

If you play Tokyodoku, the closest things to it in the catalogue are CarGuesser, Cardle and Planespottle. They sit in the same transport category. See the full list of alternatives.