Great emphasis has been put on security and public safety since the infamous Boston Marathon bombing that took the lives of there and left over 150 people injured. Another 130 lives were taken in last year's Paris bombing. 

According to The Japan Times, both public protectors and private companies joined forces and know-how, to make the 2016 Tokyo Marathon as safe as possible. 

At the entrance gate 900 competitors (or 2.5 percent of the competitors) had their pictures and numbers taken from a face authentication system provided by a Secom Co. security firm. These images were then checked against photos registered in advance. Additonally, the firm's airship was reported to have flown above the finish line, taking aerial photos and forwarding them to the Metropolitan Police Department, which was also getting videos from a drone, provided by another security company.

On top of that, Tokyo police arranged for several interceptor drones to be on stand by. They were set up to capture any suspicious-looking drones, entering the protected area. 

The Tokyo Times also reported that this was "the first time the Tokyo Marathon had been aerially monitored for security purposes."