Abe's assassination must have been a shock for the Japanese. Was it as much of a shock for them as the Olaf Palme assassination was for the Swedes or the Utøya Island mass murder was for the Norwegians?
Somehow I don't think so. Sweden, Norway, and Japan pride themselves on being peaceful, close-knit countries, but I suspect the Japanese are more realistic and suspicious about what people are really capable of even in peaceful, close-knit countries.
Government by assasination was common in post-Mejii Restoration Japan (1868) up to almost WWII.
I am sure Japanese LE have that history in the back of their minds.