DT lost in translation

Okay while looking up for the lyrics of Atsushi/DT duet as requested by dtindo below, discovered some confusing details abt this song. It was also the theme song for a Japanese TV series called Hi Wa Mata Noboru aka The Sun Also Rises which of cos has nothing at all to do with Ernest Hemingway to add to the confusion. The song sung by Atsushi & called Rising Sun was then released as a single by EXILE. This TV series abt the going-ons in a police academy was screened during July this year. So was this the second time the song was released? Cos Atsushi said that he wrote the song which was actually the lyrics during the earthquake in Japan which was in March. So did he set his lyrics to the melody then or maybe the melody was written for the TV series & Atsushi decided to use the lyrics he has written a few months ago? Or did Rising Sun had different lyrics & then Atsushi decided to change the lyrics to his own for the duet with DT? The mind boggles ... also considering this song was not really a hit when it was first released since even Atsushi's fans did not know abt it, why release it again as a duet? The only answer I can think of is that maybe the Japanese TV series will soon be screened in Hong Kong & this will be the theme song again. Anyway here are the lyrics with the Japanese translated to Chinese - I don't know by who so I can't give any credits very sorry.

ATSUSHI & 陶喆 - 相信有一天
いつか悲しい思いに (有一天　懷抱著悲傷感覺)
向き合えずに 一人だけで (卻獨自一個人　無法去面對)
不安になるそんな夜は (於是感到不安的夜裡時分)
慢慢地　把手心貼近胸前
有種莫名感覺　從心的最裡面
漸漸甦醒　重新回到身邊
我知道　有一天　不怕再多試煉
誰かが光失って (因為有人失去了希望的光線)
涙がそっと溢れて (臉頰就悄悄多了兩行淚)
自分の無力さを感じて (發現自己的無力有多狼狽)
就算這樣　依然願意付出一切
分享自己　成全別人的心願
凝結成一股暖流 在身體流動　一點點蔓延
那一天　剎那間一道光線
明明隱約看見　卻曇花一現
於是又拼命追逐它的腳步
我的歌　這條路　不會有休止符
もしもすべてを失って (如果說失去了現在的一切)
涙で前が見えなくて (因為眼淚模糊了眼前的視線)
ひとりの孤独さを感じて (一個人獨自去承受孤單的感覺)
心灰意冷對一切感到厭倦
為什麼而活　為什麼盲目地追
就算困在重重迷霧不見來時路
相信有一天… いつかきっと…
あの空の彼方 (那片天的遙遠邊界)
見え始める日が (能夠看到的那一天)
必ず 来るはず (一定會來到我身邊)
幸せの意味探して (尋尋覓覓幸福的真正意念)
何度も明日を信じて (有多少次相信會有明天)
それでもくじけそうになるけど (即便這樣依然覺得被挫折包圍)
直到我心裡面背負的一切
被宣告終點的日子來臨以前
絕不會輕易去放手　此刻我願承諾
相信有一天…直到那一天…