The physical album was sold in two separate parts: the first album titled 'HyunJin' featured HyunJin solo, while the second album titled 'HeeJin & HyunJin' featured HyunJin alongside HeeJin.
- The difference between the physical albums was their CD colors, the cover images, and the photo cards that can be received at random when purchasing the CDs. All other contents of the albums are identical.
- There can be a max of two different photo cards found in the album 'HyunJin' that feature HyunJin solo, and a max of two different photo cards found in the album 'HeeJin & HyunJin' that feature HyunJin alongside HeeJin.
- Executive Producer: John Yi
- Creative Director: Jaden Jeong
- Music Producer: MonoTree, Artronic Waves, Jaden Jeong
- A&R: Yoon Do Yeon, Ryu Ji In @ BlockBerryCreative
- Recording Engineer: Lee Joo Hyung @ MonoTree Studio; Jung Eun Kyung, Woo Min Jung @ InGrid Studio
- Mixing Engineer: Alan Foster @ LAFX Studio; Yoon Won Kwon @ Studio SEAN
- Mastering Engineer: Kwon Nam Woo @ 821 Sound Mastering
- Management Director: Kim Yeong Do
- Management: Yoon In Ro, Lee Geun Mook, Seo Won Bae, Park Yong Tae, Song Yuri
- Administration: Jae Kang
- Press Publicist: HNS HQ
- Styling Director: Kim Min
- Hair Director: Lee Young Ran @ RUE710
- Makeup Director: Jang Yoo Jin @ RUE710
- Choreography: DQ
- Music Video: @ Digipedi
- Photographer: Go Ji Yeong
- Art Work: Studio XXX