(click ads for closer look)
Translation: Maruko. Bras that make your breasts look bigger.
For those of you who don't know, a "bronski" is when you smush your face between a woman's big breasts. And, as some of you may know, Japanese men are even more obsessed with women's breasts than Americans. These fellas look like they've been bronski-ing Salma Hayek. Or one of these DD-cup true.com models. true.com founder Herb Vest probably knows of the bronski.
(images scanned from Archive. Responsible ad agency is Asatsu-DK, Tokyo.)