From the game soundtrack scored by Taiwanese composer—V.K:
"戀語 [Liàn Yǔ]" (Love Language), the opening and main leitmotif track, is a soothing piano solo that puts you at ease. It also helps settle the romantic theme the game is seemingly all about.
"Level Task" gets you ready for production as you bring out your Karmas to shoot.
"Rosy Mirror" note Youtube label: "Dream." is the first music you are treated to. It is an airy tune that comes up whenever a dream-like scenario happens.
Victor's theme, "時間之間 [Shí Jiān Zhī Jiān]" (Between Time), is a soft tempo track led by the cello. It has a pompously warm, sophisticated, and soothing atmosphere with a desire for intimacy hinted in its melody.
Gavin's theme, "湛藍溫度 [Zhàn Lán Wēn Dù]" (Azure Blue Temperature), is just like him; its rhythm immediately transports you up to the vast blue sky, gives off the tempo of ocean waves and the free spirit of the wind that embodies the compassion for justice he has in his character. It starts with a few notes to set the beat, before the guitar comes rushing in. Out of all four themes, Gavin's is the most EDM-like.
"黑暗歸來 [Hēi Àn Guī Lái]" (The Return of Darkness)note Youtube label: "Back to Black." belongs to Helios and starts showing up when the chapters reach double digits. It is energetic, yet mysterious and goes along with the coldness that is so far from the warm Kiro you are used to seeing.
The incredible"極暗之時 [Jí Àn Zhī Shí]" (Darkest Hour)note Youtube label: 'Brilliance.', a rising theme that steadily builds up to a high, along with the chorus and the strings. This theme played at the premier event of the chapters 12 to 15, often during scenes where major information is revealed.
長夢 [Cháng Mèng] (Long Dream)note Youtube label: 'Sad love' is a quiet, melancholic track, encompassing a suffering that has been going on for too long.
From the anime adaption:
The anime has opening and ending themes with Chinese and Japanese versions: