On October 28, 2016 the second LOOΠΔ member, HyunJin, was revealed. The group was formed by Blockberry Creative through an 18-month-long pre-debut project.
On November 10, 2016 HyunJin's debut single "Around You" was released in a 10-minute short film format music video. Six days later, the music video for HeeJin and HyunJin's collaboration song "I'll Be There", filmed in Tokyo, was released, along with the official music video for "Around You".
LOONA’s upcoming first world tour takes the group to 9 different cities across the United States and kicks off in Los Angeles on August 2, 2022
In February 2023, HyunJin and ViVi became the final members of LOONA to file injunctions to suspend their contracts with BlockBerry Creative.
On June 12, 2023 it was announced that HyunJin and ViVi have joined a new agency CTDENM established by Yoon Do Yeon, who was previously a director in BlockBerry Creative’s planning division and who also worked at SM Entertainment in the past.