This is popular Japanese story is about a poem called "Tomino's Hell." They say that you should only read with your mind, and never out loud. If you were to read it out loud, then you must take responsibility for your actions. "Tomino's Hell" (トミノの地獄) is written by Yomota Inuhiko (四方田 犬彦) in a book called "The Heart is Like a Rolling Stone" (心は転がる石のように), And was included in Saizo Yaso's (西條 八十) 27th collection of poems in 1919. It's not sure how this rumor started, but there's only a warning that "If you read this poem out loud, tragic things (凶事) will happen." It just looks like a curse. It asks to not compare this with the common "You'll grow taller" or even "My parents died." Do you get a sense of how dangerous this is?
This story used to be very popular in 2ch, and there were many people taking pictures and videos as proof and posting them on 2ch. There were many users that said that nothing happened, but there were also many posts that didn't have the user come back to post the results. I think it's scarier than someone posting that someone else got sick or that someone else passed away. But if you were to read it out loud, it's better to read it in Japanese rather than the translation.
Tomino no Jigoku (Tomino's Hell)
ane wa chi wo haku, imoto wa hihaku,
His older sister vomited blood, his younger sister vomited fire,
kawaii tomino wa tama wo haku
And the cute Tomino vomited glass beads.
hitori jihoku ni ochiyuku tomino,
Tomino fell into Hell alone,
jigoku kurayami hana mo naki.
Hell is wrapped in darkness and even the flowers don't bloom.
muchi de tataku wa tomino no aneka,
Is the person with the whip Tomino's older sister,
muchi no shubusa ga ki ni kakaru.
I wonder who the whip's shubusa(?) is.
tatake yatataki yare tataka zutotemo,
Hit, hit, without hitting,
mugen jigoku wa hitotsu michi.
Familiar Hell's one road.
kurai jigoku e anai wo tanomu,
Would you lead him to the dark Hell,
kane no hitsu ni, uguisu ni.
To the sheep of gold, to the bush warbler.
kawa no fukuro ni yaikura hodoireyo,
I wonder how much he put into the leather pocket,
mugen jigoku no tabishitaku.
For the preparation of the journey in the familiar Hell.
haru ga kitesoru hayashi ni tani ni,
Spring is coming even in the forest and the stream,
kurai jigoku tanina namagari.
Even in the stream of the dark Hell.
kagoni yauguisu, kuruma ni yahitsuji,
The bush warbler in the birdcage, the sheep in the wagon,
kawaii tomino no me niya namida.
Tears in the eyes of cute Tomino.
nakeyo, uguisu, hayashi no ame ni
Cry, bush warbler, toward the raining forest
imouto koishi to koe ga giri.
He shouts that he misses his little sister.
nakeba kodama ga jigoku ni hibiki,
The crying echo reverberates throughout Hell,
kitsunebotan no hana ga saku.
The fox penoy blooms.
jigoku nanayama nanatani meguru,
Circling around Hell's seven mountains and seven streams,
kawaii tomino no hitoritabi.
The lonely journey of cute Tomino.
jigoku gozarabamo de kitetamore,
If they're in Hell bring them to me,
hari no oyama no tomebari wo.
The needle of the graves.
akai tomehari date niwa sasanu,
I won't pierce with the red needle,
kawaii tomino no mejirushini.
In the milestones of little Tomino.
( Source: http://tinyurl.com/45xuebv )