Personally I think it's beacause the pressure to success is really big in Japan, that combined with many young people not getting attention beacause their parents work so much (and we all know japanese people work hell of alot) gives a high suiciderate.
【一家心中】 [いっかしんじゅう]
family suicide
【介錯】 [かいしゃく]
suicide assistant
【狂言自殺】 [きょうげんじさつ] faked suicide
【決死隊】 [けっしたい]
suicide corps
【後追い自殺】 [あとおいじさつ] (vs) following someone's example, and committing suicide
【合意情死】 [ごういじょうし] double suicide
【合意心中】 [ごういしんじゅう] double suicide
【死に装束】 [しにしょうぞく]
burial clothes/clothes worn to commit suicide
【
自害】 [じがい] (n,vs) suicide
【自決】 [じけつ] (n,vs) self-determination/suicide/resignation (from a post)/(P)
【自殺】 [じさつ] (n,vs) suicide/(P)
【自殺を図る】 [じさつをはかる] (exp) to attempt suicide
【自殺者】 [じさつしゃ] person who commits suicide
【自殺未遂】 [じさつみすい] attempted suicide
【自殺幇助】 [じさつほうじょ] (the crime of) aiding and abetting a suicide
【自刃】 [じじん] (n,vs) suicide by the sword
【自尽】 [じじん] (n,vs) suicide
【自爆】 [じばく] (n,vs) suicide bombing, e.g. crashing one's plane into a target/self-destruction
【自爆攻撃】 [じばくこうげき]
suicide bomb attack
【自縛霊】 [じばくれい]
ghost of a suicide victim
【殉死】 [じゅんし] (n,vs) dying a martyr/following someone in suicide
【焼身自殺】 [しょうしんじさつ] burning oneself to death/suicide by fire
【情死】 [じょうし]
double love suicide
【心中】 [しんじゅう] (n,vs) double suicide/lovers suicide/(P)
【生害】 [しょうがい]
commit suicide
【相対死】 [あいたいじに]
double suicide
【体当たり】 [たいあたり]
body blow/ramming (suicide) attack
【体当り】 [たいあたり]
body blow/ramming (suicide) attack
【投身】 [とうしん]
suicide by jumping into a river (base of a waterfall, from a high place)
【特攻隊】 [とっこうたい]
suicide squad/(P)
【特別攻撃隊】 [とくべつこうげきたい]
suicide squad/kamikaze group
【入水】 [じゅすい]
suicide by drowning/drowning oneself
【入水】 [にゅうすい]
suicide by drowning/drowning oneself
【飛び込み自殺】 [とびこみじさつ] committing suicide by throwing oneself in front of an onrushing train
【無理心中】 [むりしんじゅう]
forced double suicide
But maybe they commit so much suicide cause they have so many words for it and they want to be able to use all of them? :?
(thx to
http://poets.notredame.ac.jp/cgi-bin/jedi-inon(search for suicide) for help with the list ^^)