such a cute song omg i love these lyric's they're so adorable i actually thought the 2nd "(ja nae son japgo)" was sunny but the more i listen to it actually does sound like sooyoung, especially in her cutesy voice!! yeah imo it sounds more like sooyoung's cutesy voice than sunny's, i see why some other people also think its sunny tho!!! sunny, yoona and sooyoung can sound similar to one another times

BUT i know their voices very well so i can confirm that its sooyoung's line lol

Members + Color Codes

Taeyeon (Purple)
Jessica (Dark Blue)
Sunny (Orange)
Tiffany (Pink)
Hyoyeon (Green)
Yuri (Red)
Sooyoung (Light Blue)
Yoona (Yellow/Gold)
Seohyun (Teal)

Album: The Boys
My Bias: Tiffany, Yuri, Yoona
Release Date: October 18, 2011

Translation Source: https://colorcodedlyrics.com/2011/10/23/girls_generation_-_bitamin_vitamin_cc_lyrics/