歌名有點怪，歌曲有點怪，MV更怪的一首歌。
下面是作詞人為歌名及歌曲的解畫，幾個月前仍然完全看不懂，但沉澱一番後，卻發現原來是多麼的直白。

"The friction between the brevity of human life and the anxiety caused by it.
Humans understand life when faced with death.
The understanding of life also means to imagine the end of your own life.
That is when you understand the speed of life and become anxious.
The unbelievable speed of life, and our own anxiety towards it.
This friction that sets off sparks is what makes us finally live. "

- Hiromu Akita (Writer of the lyrics)

速度與摩擦 (啟發自 秋田ひろむ)

生命之短，猶如煞不住的列車
終焉之日，催生止不住的憂慮
踩下制動，是謂對速度的摩擦
輪間火花，成為曾活著的憑證

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不是怎麼今次聽這首歌和看這解釋時，腦海中很具體地出現了高速行駛的火車的形象，一切的內容便彷彿變得理所當然，沒有疑惑。