In Japan AIDS has not hit the headlines these days. HIV infection has been, however, gradually spreading for the last 20 years. It is estimated that more than 65 million people (over 1% of World Population) contracted HIV so far and 42 million people are now living with HIV/AIDS. The hardest hit area is Africa. It is true that the number of PLWHAs (people living with HIV/AIDS) in Japan is significantly small compared with the world numbers, but the annual new cases of HIV infection and AIDS diagnosis have continued to increase. In 2001, a record number of nearly 1000 new HIV infection and AIDS cases was reported.

Socio-behavioral surveys have revealed rapidly changing sexual behaviors among more Japanese: earlier sexual experiences in teen-agers, more people having so called "Casual Sex," and sex itself being diversified. Other STIs (sexually transmitted infections), which can lead to HIV infection, also have been increasing. Especially the increase of chlamydial infection, which rarely shows clear symptoms, is considered a grave concern. Condom use is widespread among young people. There is, however, an alarming tendency of having sex without using condoms with non-regular sex partners. Accordingly, it is believed that Japanese young people tend to associate the use of condoms with the prevention of pregnancy rather than with the prevention of HIV/AIDS or other STIs.