HELLO! [Credits] Lyrics by 김시원 Composed by 김시원 Arranged by 김시원, 희도 Bass by 한민규 Electric Guitar by 한민규 Acoustic Guitar by 한민규 Keyboards by 김시원 Drums by 김시원 Vocal by 김시원 Chorus by 김시원 Mixed & Mastered by Stally