Most shogi games between experienced players never reach checkmate. When a player sees that mate can't be avoided, they resign 投了 — bow slightly and say makemashita 負けました, "I have lost."
Resigning isn't giving up early; it's recognising the result. Playing on in a hopeless position, hoping the opponent blunders, is considered poor manners in over-the-board shogi — though between beginners, playing it out is how you learn to finish.
Resigning on this site
Press Resign in the game panel and confirm. The game ends at once, your opponent is told, and a 負けました bubble appears for you — you don't need to type anything.
The site also has draw offers (the opponent must accept) and impasse declarations (next lessons). After the game, both players can send ありがとうございました ("thank you for the game") from the reaction bar, and offer a rematch.
Try it
Try it: Deliver the mate Gote would have resigned to.