The first collaboration single between Lisa Halim, a female singer-songwriter representing the Japanese surf music scene, and Cunimondo Takiguchi, the most important figure in the CITY POP/CITY MUSIC scene, on-unit "Ryusenkei"! In 2021, the single "Kimi to Blue" produced by Cunimondo Takiguchi was released and became a hit among fans of nautical city pop, which led to this collaboration with Ryusenkei! "Koi ha jealousy" is an extremely comfortable fusion of Hawaiian AOR and CITY POP. Feel the match and groove of Ryusenkei's performance and Lisa's gentle vocals. She will also make a guest appearance at Ryusenkei's live performance at Billboard Tokyo on 3/21 (Tuesday, national holiday)!