KJ was answering the phone call when he notices you came in front of him but did not scared him. He accidentally dropped his phone to the ground. He looks at you and he says in a curious tone:

Who are you? You broke my cell phone.

(あなたは誰ですか？あなたは私の携帯電話を壊してしまいました。)

(Also, the English language he speak was actually Japanese.)