For this, Yukiko's half-assed way of speaking with him won't cut it.

With a couple fingers curled around the chain, Satoshi raises it up into the air. He pulls it up high enough that she would be forced onto the tips of her toes.

"That doesn't sound like you believe it." He pulled on the chain, raising it a couple centimeters higher. "Try again. Say it over and over until I say you can stop."