As Elvis left his enormous imprint on the world in the 50s, The Beatles did the same for music in the 60s as well. In Japan, the Fab Four planted seeds in a lot of young folks' heads. And pretty soon, before you can say Herman's Hermits three times fast, the Group Sounds era was born. According to Mark Schilling in his book, "The Encyclopedia of Japanese Pop Culture", one of the pioneering bands was The Spiders, a former rockabilly group, which released "Furi, Furi"(Shake, Shake) in 1965...perhaps a tribute to The Beatles' "Twist and Shout".
Pretty soon, you had other bands with names like The Carnabies, The Blue Comets, The Tempters and The Jaguars. Then, there were The Tigers which may have been the most popular GS group of them all. The collective GS band members emulated that early Beatles' look of moptops and turtleneck sweaters and tight suits.
The Tigers debuted in 1967 with "Boku no Mari"(僕のマリー...My Mary). This song, "Hana no Kubi Kazari"(A Flower Necklace) came out in March 1968 and resided at the top of the charts for 7 weeks from April 15 to May 27. The lead vocal here was Katsumi 'Topo' Kahashi （加橋かつみ）; he was given the nickname since he resembled the cute Italian mouse character, Topo Gigio. The other vocalist was Kenji 'Julie' Sawada （沢田研二）whose nickname was from singer/actress Julie Andrews. His career seemed to predestine the plot for "This is Spinal Tap" since he went from cute Group Sounds vocalist in the 60s to a David Bowie/Ziggy Stardust rocker by the early 80s. He's the one you see in the video frame before you press 'Play' in the video below.
The heyday of the Group Sounds apparently lasted from 1967 to 1969 with The Tigers disbanding in 1971. After that, the trend of New Rock came into being with bands like Happy End.