For American lawyers accustomed to struggling with massive walls of law books and expensive database services, one of the great things about Japanese law is that it is so compact and accessible.
In fact, most of what you will ever need to know fits into the roppō (六法), a small book containing a set of essential Japanese laws.
Roppō literally means "six laws" and originally referred to the six hōten (法典, codes) that are the foundation of Japanese law: the Kenpō (憲法, Constitution), Keihō (刑法, Penal Code), keijisoshōhō (刑事訴訟法, Code of Criminal Procedure), Minpō (民法, Civil Code), Minjisoshōhō (民事訴訟法, Code of Civil Procedure) and Shōhō (商法, Commercial Code). All have their roots in laws that were adopted during the Meiji Era (1868-1912) and are based on continental European models.