K-pop is an abbreviation for Korean pop music, and it is indeed, taking over the world by the 'Korean wave' (한류).
It has its influence all around the globe and it reaches diverse audiences. K-pop idols or singers give powerful performances in the form of songs and dances.
In the past decade, Korean entertainment companies (which train and debut K-pop idols) have begun making Japanese versions of Korean songs. This is because Japan is very close to South Korea and their aim was to attract the audience in Japan.
Old school artists like 2PM, Bigbang, SNSD, etc had been famous in Japan and held many concerts for their Japanese fans.
Currently, the Grammy nominated boy band, BTS is the most famous artist in Japan. They had also released several albums in Japanese and their latest single, 'Stay Gold' is getting fame in Japan. They also released a song, 'Your eyes tell’ for the title track of the Japanese movie, 'Spiral Labyrinth – DNA Forensic Investigation'.
After BTS, TWICE gets the most fame in Japan. Twice is a nine-member girl group with three Japanese members, who had been famous ever since their debut in 2015.
All artists conduct fan meetings and hi-touch events in Japan and communicate with their Japanese fans. Most of the Korean artists are fluent in Japanese, which is a basic skill for them.
JYP entertainment (an entertainment company), especially include Japanese artists in their groups.
Recently, JYP entertainment also held an audition programme based in Japan, named 'Nizi project' and debuted a nine-member girl group called 'NiziU', who are becoming extremely popular in Japan.
Boys Over Flowers (꽃보다 남자) is a 2009 South Korean television series that is based on the Japanese Shōjo manga series Boys Over Flowers written by Yoko Kamio.
In all, the future of Korean music and culture in Japan is bright and same is the future for Japanese language in Korea.