She had been in the early stages of a comeback, releasing a single for the Japanese market and touring in the cities of Fukuoka, Osaka, Nagoya and Tokyo between November 14-19, according to media reports. The news comes half-a-year after Goo was found unconscious as a result of an apparent suicide attempt.
Goo, real name Goo Ha-ra, and also known under the single name Hara, was a former member of the five-part girl group Kara from 2008 to 2015.
Goo Hara was a prominent South Korean singer and actress.
Although a cause of death hasn't been confirmed yet, many fans showed concern over Goo's happiness after she was involved in public disputes with an ex-boyfriend who claimed to be assaulted by her previous year, the outlet further reported.
It can be remembered that Hara was one of the celebrities who expressed extreme grief during the death of her best friend, Sulli, last October 14.
An acquaintance who tried to visit Hara in her Cheongdam home reportedly found her body and called the Seoul Gangnam Police, who are now investigating the case.
Goo subsequently said on Instagram that she "had been in agony over a number of overlapping issues", but would "steel (her) heart and try to show up healthy." according to an ST translation. Last year, Goo Hara had been making headlines when her boyfriend revealed that she had assaulted him.
Goo's last post on Instagram, published Saturday, was a photograph of herself in bed with the caption: "Good night". It's not clear what caused her death. Under Ogi, Goo appeared on TV shows and major fashion events in Japan.
Goo's fans also filled her Instagram with condolences in various languages, majority centering around Goo reuniting with Sulli, a close friend, in the afterlife. Things took an ugly turn when the actress accused her ex-boyfriend of threatening her of leaking her private videos on social media.