"Runaway"(not to be confused with the Del Shannon classic) was the band's debut single as a professional unit. At the time, there were some interesting trends happening in popular music: technopop was huge, thanks to The Yellow Magic Orchestra, the second wave of aidoru started with Seiko Matsuda（松田聖子） and Naoko Kawai（河合奈保子）, and there was an interest in emulating American pop of the 1950s. Because of that last factor,"Runaway" became a runaway hit for The Chanels with sales in excess of 1 million records. The song also was at No. 1 from late April to early June 1980, and it ended up becoming the 4th-ranking song of that year. The song, by the way, was written by Reiko Yukawa（湯川れい子）and composed by Daisuke Inoue（井上大輔）.
A few years later, The Chanels would be forced to change their name since the cosmetics giant, Chanel, started lodging complaints. Therefore, the band became The Rats & Star...which is, by the way, a palindrome. As for the derivation, and I'm getting this from Wikipedia, it was thought that even scurvy rats in the bad part of town could become stars through the singing of doo-wop. Hey, whatever works, man.