The popularity of Brave Girls continues to skyrocket these past few weeks. With the delayed success of "Rollin," the four members of the K-Pop group have since been busy promoting their existing and future music releases.

Amid the height of the attention, though, former member Hayun broke her silence about her exit from the band. Koreaboo said that this is her first time to speak about the matter, revealing why she left in 2018.

Taking her thoughts to Instagram, the K-Pop idol posted a photo, alongside her detailed explanation. She said that it was because of her "hormone disorder, called hyperthyroidism."

The former Brave Girls idol revealed that her condition worsened during the promotions years ago. Due to the struggles in her health, she and her agency "concluded" that she had to leave for her own safety.

Hayun stated, however, that she feels "regretful," and apologized for breaking her silence "so late." She consequently gave her fans and followers an update regarding her health. The K-Pop personality claimed that she is still dealing with the same health condition, adding, though, that she is doing much better after focusing on treatments.

Hayun, in the end, expressed her support toward her former co-members. She said that she is "really happy" that the "Rollin" is now "finally seeing the light."

Hayun joined Brave Girls in 2016, and was also, part of the lineup that released "Rollin." During the re-release in August 2018, though, she no longer participated in the whole process. In the same month, she officially left the group without releasing her reasons.

These days, she remains active on various social media platforms, like TikTok. She is, also, working on her own channels on YouTube and Twitch.

In November 2020, Hayun signed a deal with Sandbox Network, a digital entertainment company. As for her future projects, however, she did not reveal anything other than saying that she will soon "embark on individual promotions."

Meanwhile, the four active members of Brave Girls are getting all the attention these past few weeks. The buzz surrounding them has become even more evident upon announcing their song collaboration with Lotte Department Store.

AllKpop reported that the song titled, "Red Sun" is part of the Song for You Project Volume 2, alongside the brand. It officially premiered on YouTube on Tuesday, and will play at Lotte Department Store locations nationwide.

There are speculations, as well, regarding the group's official return this year. While no confirmations have been made, they are, reportedly, planning for a "summer comeback."