Natsumi and Miyuki are testing a rebuilt motorcycle when a biker races with Natsumi. She wonders who this could be, since his riding style is just like Ken's. Ken denies it and when the girls see the rider again they give chase. He loses them in traffic but Ken arrives proving that he's not the biker. They find out that it is Ken's father Daimaru instead. He gets the wrong idea that Ken is engaged to Natsumi since she is a good biker also. Can Natsumi get Ken and Miyuki together in front of his father so that he can see the truth that they all hide?