In my two years in Tokyo, I’ve been on trains that have been delayed/stopped because of a suicide jumper half a dozen times. Delay-times range from fifteen minutes to several hours.
I’ve heard that the family of jumpers can be fined several thousand dollars (which usually doesn’t happen, but it can) – by the rail company, to compensate for delays and stuff.
I’ve never known anyone who has committed suicide by jumping in front of a train. The closest I’ve gotten is the family members of some of my Japanese friends.
In my experience, rather than a “this is so sad, they were so young…” it’s a “that was incredibly selfish, to kill yourself in a way that inconveniences so many people” attitude regarding train-suicides in Japan.
But those are just my own experiences dealing with Japanese people mostly in their 20s and 30s.
In any case, I still find suicide (regardless of the age/country) incredibly sad.