Girl group Mamamoo WHEEIN will release a solo album in a surprise move.

Mamamoo WHEEIN will release her second solo album "Soar" on Sept. 4, her agency RBW said. It's a highly complete Shinbo full of WHEEIN's colors, and Jung Ki participated in the production," it said.

With this, WHEEIN will return as a solo artist in one year and five months after her first solo album "Magnolia," released on April 2018.

In particular, it is the second time WHEEIN has been working with Jung Ki and the two have formed a relationship through "Anymore" in March 2017.

Since the release of "Boo Anymore," there has been a steady stream of requests by the two, along with hot reviews from music fans. WHEEIN and Jung Key are expected to give a deeper impression through "Soar."

In addition, WHEEIN released a web jacket image and the teaser video for its title song "GOOD BYE" on its official SNS at 0:00 p.m. today (June 29), and started the countdown in earnest.

In the photo released, WHEEIN creates a dim mood with a deep, dreamy look.

Wearing slightly disheveled hair and a brown jacket, WHEEIN exudes an autumn vibe with a delicate expression of emotion and is admired by viewers.

WHEEIN has been recognized for her outstanding singing ability as well as her attractive voice through various OST and music sources, including Mamamoo album.

In addition, WHEIN is expected to show her true value as a luxury vocalist through "Soar" as it is considered the "end of feeling" king, showing a wide range of perforances ranging from dance to ballads.

Meanwhile, WHEEIN's solo album "Soar" will be released on various music sites on Sept. 4.