Gokuitten

In the year 20XX, a new virus with a fatality rate of over 90 percent began spreading across the world. This caused mass panic, until scientists determined that the sole carriers of the virus are women with massive breasts that are D-cup or larger. Fearing an increase in the infection rate, the government of Japan enacted the "Massive Breasts Quarantine Act", which requires that any woman whose chest is over that size be incarcerated in a concentration camp. Yuuki Kishida, a male high schooler who is so androgynous that he is often mistaken for being female, often spoke fondly of his supposedly "small-chested" fiancée Ayaka Nanase to his friends... But then his happy days took a sudden turn for the worse! While walking down the street one night, he gets attacked by a hoodlum, and when he comes to... he finds that his own body now has massive breasts, and he is being sent to the SICS concentration camp where all the "dangerous" big-breasted women are being gathered! What in the world happened, and will he be able to survive while completely surrounded by huge breasts everywhere he looks?! Source: Kodansha