In the 6th entry of the series, 1965's "Ereki no Wakadaisho"(エレキの若大将...The Young Man About Town of the Electric Guitar), he performed the theme song "Kimi to Itsumademo"(With You Forever), a love ballad which sold over 3 million copies and would become Kayama's trademark tune. One of the lyrics, "Shiawase da na"(幸せだな....I'm so happy), became a catchphrase of the time. Although Oricon didn't exist at the time, it did reach No. 1 on the "Record Monthly"magazine charts and would earn a special award at The Japan Record Awards of that year. In addition, Kayama would appear four times on the Kohaku Utagassen (1966, 1981, 1982, 1999) to perform the song which was originally released in December 1965.
"Kimi to Itsumademo" was written by Tokiko Iwatani（岩谷時子）and composed by Kayama himself. The pair was also responsible for the song below.
The B-side of the record is "Yozora no Hoshi" (夜空の星....Stars of the Night Sky), which has also become one of Kayama's famed songs. In fact, it also got him two further appearances on the Kohaku to perform this song (1997, 2010). His Ventures surf rock influence is very obvious here as he and his bandmates just twang on those guitars. Both songs have been chiseled into my memory as classic kayo kyoku. And both have been covered by various artists such as rock band The Alfee, former Morning Musume member Maki Goto（後藤真希） and even by The Ventures themselves.