As leader and main vocalist of TWICE, the best-selling Korean girl group of all time, JIHYO has a lot of eyes on her with the release of her debut EP. The 26-year-old artist not only has eight years of TWICE superstardom under her belt, but another decade as a JYP trainee before that. The almost two decades of K-pop industry experience shine through on ZONE, which is far more polished than a debut EP has any right to be. With songwriter and/or composer credits on six of ZONE’s seven tracks, JIHYO was actively involved in many stages of the record-making process. Groovy, upbeat opener “Killin’ Me Good” veers closest to TWICE’s trademark sound. In it, JIHYO mostly stays in her lower register, crooning about giving herself over to a new attraction: “You're makin' me feel so brand new/You're killin' me, killin' me good.” She explores similarly sensual themes in soulful B-sides “Closer” (“I just can't leave you alone/Can we get even closer, babe?”) and “Wishing on You” (“In a dream that I dream with my eyes open/Love me at the end of my lips”). Things get more complicated in “Talkin’ About It”, featuring American singer 24kGoldn, where JIHYO explores the intensity of pursuing a relationship in the public eye: “Run away, let's leave the pressure, you are all I need forever.” In the album-ending belter “Nightmare”, JIHYO invokes the same suggested escape, this time urging someone else to run away from her. Korean singer-songwriter HEIZE lends her wispy vocals to “Don’t Wanna Go Back”, a duet about moving on after a breakup, while “Room” gives us a kind of conclusion to this story in JIHYO’s determination to leave the past in the past. “I'm not coming back to this room,” she sings in the song’s chorus before repeating the "Not coming back, coming back" refrain for the song’s hypnotising outro.