"Ai wa Katsu" (愛は勝つ,literally "Love will win") is a song composed and recorded by Japanese singer-songwriter Kan, released as the artist's eighth single in September 1990. It was initially featured on his album Yakyū Senshu ga Yume datta, issued a month before the single came out. The song became the performer's first charting hit and the most successful single with sales of over 2 million copies, and has been regarded as his signature song.
"Ai wa Katsu" is the lead-off track of Yakyu Senshu ga Yume datta, the composer's fifth studio album which was released in July 25, 1990. It was used as the opening theme of quiz show aired on TV Asahi during the summer 1990, and released as the second single from the album.
Kan had previously released seven singles at the time, but none of them entered the chart. Polydor Records had not anticipated it would be a big hit, and issued only 10,000 copies of CD singles at the first pressing. Therefore, "Ai wa Katsu" had not attained immediate chart success upon its release.
To promote his new album, "Ai wa Katsu" first obtained intensive airplay on radio stations of Kansai district. The song had gradually captured more attention in the country's other regions, providing the artist with the first chart entry. It was also featured on the popular variety show Yamada Katsutenai TV aired on Fuji Television, lifting the single to the summit of the Japanese Oricon sales chart by the end of 1990.
"Ai wa Katsu" spent 8 weeks atop on the Oricon chart, ranking at the number-three on the country's best-selling singles list of 1991. Sales of the single surpassed 2 million during its chart stay of 52 weeks.