Also, on the premise that we start one-to-one fighting by signal, whatever the rules of game are (even without banned skills or techniques), it's difficult for us to acquire the skills that include surprise moves, hidden weapons and so on.
また、どんな試合規則にしても（禁止技無しでさえ）一対一で合図と共に戦いが始まることが前提となり、不意打ちや隠し武器などを想定した技術までカバーすることは難しい。