Short answers, pulled from the story.
City pop is a loosely defined form of Japanese pop music that emerged in the mid-1970s and peaked during the 1980s. It grew from Japan's Western-influenced "new music" scene and incorporated styles including funk, disco, R&B, AOR, soft rock, and boogie. The term itself was coined by Japanese record companies and music magazine editors in the late 1970s to describe music with an urban and sophisticated atmosphere.
Tatsuro Yamashita is sometimes called the "king" of city pop and is one of its most successful artists. Haruomi Hosono, who founded the band Tin Pan Alley in the mid-1970s, is credited as a key influence. Yellow Magic Orchestra and its members are also credited for shaping the mixing and arrangement styles central to the genre. Sugar Babe, which included Yamashita and Taeko Onuki, released a 1975 album considered a pioneer of city pop.
City pop lost its mainstream appeal after the 1980s and was derided by later Japanese generations. Yosuke Kitazawa described how many Japanese people who grew up with the music came to consider it cheesy, mainstream, and disposable, with some calling it "shitty pop." The genre's close association with Japan's economic bubble made it feel dated as that era passed.
City pop's revival began around 2010 through music-sharing blogs and Japanese reissues that introduced the genre to international music listeners. YouTube's recommendation algorithms then amplified individual songs to a global audience. Mariya Takeuchi's 1984 song "Plastic Love" became a central example of this viral rediscovery.
City pop became an important touchstone for both vaporwave and future funk, two sample-based microgenres that drew on the textures and aesthetics of city pop recordings. The city pop revival in the early 2010s was partly driven by the same online communities that developed these microgenres.
"Mayonaka no Door (Stay with Me)" by Miki Matsubara is a city pop song that experienced a major resurgence in 2020. It reached the number one spot on Spotify's global viral chart for the week of 10-the 16th of December 2020 and broke into Apple Music's J-pop top 10 in 92 different markets, making it one of the most prominent examples of the international city pop revival.