When you plan a trip abroad, one of the factors you might consider is travel safety and risks. For example, Syria used to have many stunning places. But do you like to go to Syria right now? Probably not. Nobody wants to go to the front lines of the war by risking everything, right? One of travel risks you come to your mind at first is robbery. How to keep your belonging safe ultimately leads to happy travel memories. These days terrorism is a priority to examine also. It jeopardizes your life.
If Tokyo is your destination, Tokyo/Japan would be a good option in safety aspect. (8th rank according to Business Insider issued in 2017, http://uk.businessinsider.com/worlds-safest-countries-global-peace-index-2017-6) . I would say, every country including Japan has thefts, pickpockets, scams and frauds but it is less likely for travelers to encounter such troubles in Japan. Maybe you would be surprised to see kids in Japan walk alone in the night. It is said that such peaceful circumstance spoils Japanese people.
However, you should be careful in a rough area.
Kabukicho (in Shinjyuku)
Kabukicho is one of the most famous a red-light district in Japan. Owners in many shops are Yakuza, mafia, gangsters, or whatever it’s called. If you do not know where to eat/drink, you might be absurdly charged a high price. As long as you walk around and see neon advertising signs, it is totally fine. You can see touting on the streets but it’s illegal.
Unlike other countries, drugs are highly regulated in Japan. But it is sometimes reported that there are illegal drug dealings in Roppongi. It is maybe because this is an area where a lot of foreigners and rich people gather with or without temptations.