《Reason》是玉置成實演唱的一首歌曲，填詞：玉置成實，譜曲：玉置成實，歌曲收錄在《Reason》同名EP中。
歌詞如下：
I'm on my way to where I know
It's better for me to stay
With you beside me
Cause I believe in what we are
Reason why I'm feeling so alive
When I'm with you
Reason why I'm smiling inside
It's you
Reason why I'm singing this song
To all the world
Cause you and I
Can make it through the rain
So much stronger than before
With every storm we'll share the sky
Cause you and I are building strong
And now the world knows
Reason why I'm feeling so alive
When I'm with you
Reason why I'm smiling inside
It's you
Reason why I'm singing this song
To all the world
Your not always there
When you want her to be
So don't be afraid to let your feelings out
Time goes by so fast the days
Can seem so hard to find
The reason for my pain
Was a mirror of what might have been
Your future's only yours to shine
If you're ready to write your own line
Cause every word has power, they create your destiny, believe it!
You and I can make it through the rain
So much stronger than before
With every storm we'll share the sky
Cause you and I are building strong
And now the world knows
Reason why I'm feeling so alive
When I'm with you
Reason why I'm smiling inside
It's you (x3) yeah, it's you, yeah, it's you. Why do I sing? Cause of you. 一切苦楚隨風飄逝，微笑地，跟你走，風雨裏都有你。放眼望見我們打造的一片天氣，共你同行無疑。理由在何處？感覺如此活著，全為你。世界聆聽著這首歌，只為你。原因是我和你能渡過雨天，無懼暴雨，共建堅強。原因在何處？微笑底，全為你。只為你。我要高歌一曲，只為你。只為你。只為你。只為你和我。只為你和我。只為你和我。只為你。只為你。只為你。只為你和我。只為我。只為我們的愛情。只為我們的未來。只為我們可以創造更多的驚奇！更多可能性！你我都可以，因此唱出歌聲裡的話語和詩篇，勇往直前吧！因為只有自己才有可能成為真愛、自信、自由的那一種風格的人。永不停止奔向無窮的新旅程與美好奇遇的激動心情！讓我們一起展翅高飛吧！你我都可以！因此唱出歌聲裡的話語和詩篇，勇敢前行吧！