After making his debut as a Vocaloid producer in 2024, mar_songwriter, who has been continuously charting in the top ten in the Chinese region, has poured his power into this Vocaloid rock song for Hatsune Miku in Japan and overseas. The song "City Girls Mission", which will be digitally released this time, is themed on Sapporo City, where Hatsune Miku was born. It is an original Vocaloid song written, composed and arranged by mar_songwriter. "I created this song with a rap-like melody as a song full of power and happiness," mar_songwriter commented. The jacket is a striking and very eye-catching illustration of an ordinary high school girl and a city girl who has transformed into red and is heading out into the city at night.