A muggy summer day... Rina, returning from shopping, tries to enter her house but accidentally slips and spills her belongings. Just then, Yamada, who lives next door, also returns home. As Yamada helps Rina pick up her things, he notices the sweat on the back of her neck flowing down like it's being sucked into the valley of her chest. It's easy to imagine from the depth of that valley that Rina's breasts are incredibly large, and it's clear that the protruding objects poking out from the fabric of her clothes are her nipples... Knowing that Rina is not wearing a bra, Yamada's reason is driven mad.
