How much sexual knowledge adults should give teens has been debated for decades to reduce teen pregnancies and sex-related diseases. According to the National Campaign to Prevent Teen and Unplanned Pregnancy (2013), the United States has the highest rate of teen pregnancy among developed countries, and approximately sixty-eight out of every thousand girls became pregnant in 2008. To change this, the United States provide two types of pregnancy sex education: abstinence-only sex education and comprehensive sex education. In contrast, Japan has one of the lowest rates among developed countries. Adding the dates of birth and abortion, at least 34,220 girls became pregnant in 2011 (Japanese Ministry of Health, 2011). Even though Japan has fewer teenage pregnancies, the lack of practical knowledge about sexuality has caused several tragic incidents in recent years. To provide sexual knowledge to children, Japan provides fact-based sex education. Furthermore, sexually transmitted infections (STIs) are becoming a serious problem lately. According to the World Health Organization, 490 million people contract sexually transmitted diseases every year (2013). To avoid teenage pregnancies and sexually transmitted diseases, sex education plays an important role for teenagers. However, because there are different programs, what teens learn is different depending on the type of sex education. Among the three types of programs offered in the United States and Japan, comprehensive sexuality education is the most effective. This article focuses on sex education in the United States and Japan and describes its characteristics and effectiveness. Abstinence-based sex education is a type of sex education in the United States. It is a program that aims to prevent teenagers from becoming pregnant by emphasizing the importance of abstaining until marriage. Second...... middle of paper...... hūkyō Television Broadcasting. Nagoya City, Aichi Prefecture. May 12th. 2013.Santelli, J., Ott, A., Lyon, M., Rogers, J., Summers, D., &Schelifer, R. (2006). Abstinence and abstinence-only education: A review of U.S. policies and programs. Journal of Adolescent Health 38 pp72-81. Conflict over US sexuality information and education. (n.d.). An explanation of federal funding for more comprehensive approaches to sexuality education. Reserved by http://www.siecus.org/index.cfm?fuseaction=Page.ViewPage&PageID=1262 Stanger-Hall, K. & Hall, D. (2011) . Abstinence-only education and teen pregnancy rates: Why we need comprehensive sexuality education in the United States PLoS ONE 6(10).World Health Organization. (2013). Sexually transmitted infections (STIs). Reserved by http://www.who.int/mediacentre/factsheets/fs110/en/index.html