kamt

My guess for each part:

[Jessica]Itsumo yori sukoshi hiroi heya tada hitori
It's over, guess it's over
[Taeyeon]Futari de tsukuriageta sutourii mo munashiku
Konna ni kantan ni kuzureteshimau nante

[Sunny]One mistake, got a one regret
[Seohyun]Dare mo kanpeki janaitte
[Sunny]Sou iikikasetemitemo
[Seohyun]Nani wo shitemo kizu wa iyasenakute

[All]Ima taimu mashiin ni norikonde
[Taeyeon]Anata ni ai ni yuku [Seohyun]koto ga dekita nara
[All]Mou nani mo negawanai
[Sunny]Hakanakute tooi kioku ni naru mae ni
[Jessica]I need a time machine oh
[Tiffany]I need a time machine oh

[Jessica]Hitori de sugosu jikan wa ososugite
[Taeyeon]Ayamachi no batsu wa amari ni mo omoku
[Jessica]Anata ga saigo ni nokoshita words
[Taeyeon]Ima demo zutto rifurein tomaranai
Mada mune ga itamu

[Sunny]Just one mistake, just one regret
[Seohyun]Wagamama mo ima wa itoshikute

[All]Ima taimu mashiin ni norikonde
[Taeyeon]Anata ni ai ni yuku [Seohyun]koto ga dekita nara
[All]Mou nani mo negawanai
[Sunny]Hakanakute tooi kioku ni naru mae ni
[Jessica]I need a time machine

[Tiffany]Jikuu tobikoete anata ni aetara
[Sooyoung]Tatoe onaji
[Hyoyeon]Ketsumatsu mukaeta to shite mo kitto
[Yuri]kui wa nokoranai hazu dakara

[All]Ima taimu mashiin ni norikonde
[Taeyeon]Anata ni ai ni yuku [Seohyun]koto ga dekitanara
[All]Mou nani mo negawanai
[Sunny]Hakanakute tooi kioku ni naru mae ni
[Taeyeon]Yeah futari no omoide wasureteshimau mae ni
[Yoona]Gimme a time machine oh
[Jessica]Gimme a time machine oh
[Sunny]Gimme a time machine

Not really sure about Yoona and Yuri though.
I need an MV for this.