Shoji Mori, the main vocalist and leader of the singing group Los Primos, died of heart failure on Sunday afternoon at a hospital in Tokyo. He was 70.

Mori previously suffered a heart attack in January 2007 and had to undergo surgery. He was periodically examined after that, but with his health showing no improvement, he was scheduled to be admitted to a hospital on October 19. But two days before that, on Saturday, he collapsed at home and was rushed to the hospital. By the time his bandmates arrived, he Mori had lost consciousness. He passed away the next day.

Formed in 1961, Los Primos became one of the top kayokyoku groups during the 1960s. Mori joined the group in 1965, and the following year they released their debut single "Love You Tokyo" (originally sold as a double A-side with "Namida to Tomo ni"). The song became a major hit, and when Oricon started publishing its sales charts, "Love You Tokyo" was the very first #1.

The group is still active to this day, and they even managed to go ahead with a scheduled dinner show in Saitama on Sunday, borrowing Masato Sanjo (66) of Tokyo Romantica as a replacement vocalist.