[‡ 2][‡ 3][‡ 4] On November 18 2019 (JST), via her indie label Sprite:Wall, she released her first single for the global market, a Japanese-English song entitled "Time-Lapse".

[17][18] In March 2020, she released a Japanese cover version of Doja Cat's single "Say So" in a style reminiscent of 80's city pop, which catapulted her into anti-mainstream recognition.

[10][11][19] Translated by fellow YouTuber Datenkou, the video went viral and gained the attention of Doja Cat while on an Instagram livestream after a fan suggested that she listen to Rainych's cover of "Say So".

Oh, that's right, I'm singing in my bedroom..." With praise heaped on by Doja Cat and The Weeknd,[31] Rainych's career path has surfaced to the Japanese market.

[41] On 22 March 2021, Sony Music Japan announced Rainych's first EP, consisting of 7-inch custom pink vinyl covers of "Mayonaka no Door" and "Blind Curve".

[46] On 23 June 2021, Sony Music Japan announced Rainych's second EP, which was a 7-inch vinyl record entitled "RIDE ON TIME / Say So -Japanese Version- (tofubeats Remix)".

[47][48] In early January 2022, Rainych released "Kanashimi wo Yasashisa ni" cover version to participate in the 20th anniversary of the anime series Naruto.

[50] Rainych has been praised for her appearances; Jane Su and Mika Horii of TBS Radio both described her in a single word as "kawaii".

[11][3][31][12][‡ 6] The media has represented her voice as cute, light, unique, and transparent,[51][39][52][53] and she has been referred to as an utahime ("diva", "song princess") and a "cover monster".

[55][56] Yoshihiro Kawasaki of Pony Canyon attributed Rainych's fame to her enormous influence, and stated that she had brought to the forefront anew some of the greatest Japanese works through her voice and character.

[58][59] Kento Nakajima of Sexy Zone has cited Rainych as his "favorite painter", and stated that she is an artist who draws city pop style paintings and currently attracting a lot of attention in Japan.

[1][2][10][11][‡ 1] In an interview with Withnews and J-Wave News, Rainych makes a serious effort to protect her privacy by not revealing any details about where she currently lives.

[72] Kazunari Imai of Pony Canyon remarked that this was a "classical synergistic hit" when "Mayonaka no Door" became one of the most iconic events in music streaming history.