“Welcome” is the first track and also the intro featured in IZ*ONE’s third mini album, Oneiric Diary.
- The producer of this song, also produced Secret Story of the Swan and La Vie en Rose.
- A Japanese version of this song was performed during IZ*ONE’s Oneiric Diary Digital Showcase in Japan. The Japanese lyrics were written by Hitomi.
- Lyrics by: MosPick (Korean), Honda Hitomi (Japanese)
- Composed by: Mospick
- Arranged by: Mospick
- Chorus by: 김소리(RIsso)
- Piano by: 손영진
- EP by: 예아나이스
- Guitar by: FERDY
- Synthesizer by: 강동하
- Recorded by: 이창훈 @ SWING Studio
- Mixed by: 조씨아저씨 (Assist. 전부연) @ Cube Studio
- Mastered by: 권남우 @ 821 Sound
- Translation by: Yubseyo