There are several scenarios to consider when leaving the arena. Each scenario has a different effect than other scenarios.
Scenario 1: The character is not performing any battle. The character leaves the arena.
Effect 1: The character will leave the arena with no penalty.
Scenario 2: The character is attacking an opponent. The player chooses to leave the arena.
Effect 2: You will lose 25% of your paid wager. After this, you can sign up again once you are ready to fight opponents.