I was first introduced to j-pop by watching anime when I was like 6 years old. I always loved the theme songs/ending for the shows and it just grew from there.
Maki Goto: I bought a bootleg Morning Musume CD which contained some of her solo songs. I always liked her songs the best and found it weird how it sounded like only one person was singing
I eventually found out she was a solo singer and H!P just didn't consist of Morning Musume..
Ami Suzuki: I first heard about her cause she was produced by Tetsuya Komuro who I was a fan of. I only first heard her music when she returned to the music industry with avex.
Namie Amuro: I downloaded this video called "YOU ARE THE ONE" which is a charity song made up of bands/singers produced by Tetsuya Komuro. I thought I was downloading a AMV for Final Fantasy 8 cause the description had "FF XIII" in it..
Also how I discovered other favorites like Tomomi Kahala, hitomi, and globe.
Ayumi Hamasaki: I used to really hate her and I'm not sure why. My cousin was really into Ayu and first introduced me to her. One day I decided to give her another chance and borrowed the UNITE! single from my cousin. From then on I loved her
Koda Kumi: FF X-2
Utada Hikaru: Cousin who liked Ayu
JE bands: Heard about groups like SMAP and Kinki Kids through random j-pop communities. After I randomly downloaded songs from those two groups I did more research and learned about what Johnny's entertainment was. It took me a while to like their music lol.
ULFULS: I really wanted to try j-rock and this band was recommended to me, ever since then they are one of the few j-rock bands I like. I would also always see them in those lists tv shows make (like Music Station) and always wondered what their name was.
Bonnie Pink: A local music show (YTV hit list for y'all canadians
) did a special on j-pop and her video for Private Laughter played. It was the end of the program and that was the only video I was able to see
I don't really follow her music anymore but she was one of my first favorite j-pop singers.