Japan's gun laws make them an easy mark for a terrorist shooting spree. No handguns, military rifles, machine guns, or anything they deem as an "assault rifle." The only guns their citizens can posess are certain types of shotguns and air rifles.
Obtaining a license involves a lengthy, multi-step process including a police interview, a full-day class, written and shooting-range exams (requiring at least 95% accuracy), and mental health and drug tests. Police also conduct extensive background checks that include reviewing an applicant's criminal record, employment history, financial status, and relationships with family and neighbors.
Japan also has the death penalty as a legal punishment, carried out by hanging for severe crimes like aggravated murder. They have executed about 100 inmates since 2000 and have about 105 currently on death row.