Well, talk about making an entrance. In late 1977, Shinji Harada（原田真二）made his presence grandly known on the music scene by releasing his first three singles once a month between October and December, the reason being that apparently one song was not enough to show the appeal of this singer that I've seen as the Japanese version of Gilbert O'Sullivan of "Alone Again, Naturally" fame.
His debut single was "Teens' Blues", a song that he composed with veteran lyricist Takashi Matsumoto（松本隆）behind the words. Harada is still a fellow that I'm just beginning to know, and in fact, I tried to get his debut album "Feel Happy" but perhaps unsurprisingly, it was sold out. No worries, though since there is always Xmas. Listening to some of his early hits such as this one and "Candy", I could really hear that Harada was going as far away from the typical kayo mold as possible; his melodies were arranged such that they could have been played alone on radio in my neck of the woods without anyone the wiser that these were coming from Japan. The Hiroshima native must have been fairly quickly labeled as one of the new Kings of New Music to stand next to the Queen, Yumi Matsutoya（松任谷由実）.
According to J-Wiki (there was quite a bit of text to go through so if I've made a mistake in my understanding please let me know), Harada had originally created the song while sitting on a bench along Peace Boulevard in Hiroshima. At first, the title for his song was to have been "Kimi no Sedai e"（君の世代へ...To Your Generation）with the lyrics taking on a very heavy message about world peace and the fate of the younger generation since at the time, there had apparently been an uptick in organized criminal activity to the point that it was becoming a rather large social problem.
However, the song was seen as being a little too serious so Matsumoto was brought on board to see if it could be lightened up somewhat. The recording staff saw the union of Harada and the former drummer of New Music pioneering band Happy End (はっぴいえんど) as fortuitous since Matsumoto was influenced by John Lennon while Harada was a huge fan of Paul McCartney (a bit of a reach, I know...). Still, it seems that initially there were some growing pains since Harada was told that his lyrics were a bit weak and by his own admission, he had that defensiveness of youth so there was some push back against what he saw was some potential danger of having his material overly influenced by Matsumoto.
As it turned out, the final version of the lyrics involved a certain rebellious young man turning his back on love while still wondering if he could see his former flame on the train, presumably taking her to a new city and life. So the blues of the title was brought down from its lofty societal perch to a very personal level.
The rest was history, as they say. "Teens' Blues" was the launch point for Harada's career, and it was a home run. The song became a hit and the new singer became a sensation in the music industry for his new sound...and at the teen age of 18 as well. As I mentioned above, he released his 2nd and 3rd singles in November and December respectively which were the aforementioned "Candy" and "Shadow Boxer" (that last one I'm gonna have to check out). The unusual and unprecedented decision to release his first three singles once a month paid off in dividends as all three ended up in the The Top 20 of Oricon, the first time that had ever happened.
"Teens' Blues" went all the way up to No. 6 and ended up as the 47th-ranked single of 1978. It was also indeed on that first album "Feel Happy" which hit No. 1 on the charts.