By chance, Fukaya became the lover of a very quiet and beautiful girl, Fujino, yet he worries about the vibrator she`s always carrying. "Perhaps, she considers me no more fondly than that vibrator?" In fact, their relationship began when he found her using a vibrator aboard a crowded train. Although they have passionate sex, he can`t be certain that she loves him, and feels threatened by her vibrator. Now, the two of them are going to a pool. As she will be unable to use the vibrator in the water, he expects they will be alone, but...