Recently, NU'EST member Ren uploaded a music-streaming screencap of a song on his Instagram, which naturally brought several fans to check out the song for themselves. The track was "Feel Good" by Class Mate, and to many fans' pleasant surprises, this rookie group brightened up their days with its funky beats and melody!

Even before Ren had uploaded the post, I was fortunate enough to come across the group by mere chance. Mind you, although the group officially debuted not too long ago (August 2017), the individual members in this trio have such long-term valid experiences that it almost felt natural to find them working in the industry. The three members' names are Jae Seong, Seong Jeong, and Byung Min, and to throw you some keywords related to each member, they are ASTRO, ISU (MC the Max) and Girls' Generation, respectively. Confused more than ever now?

Let's first start with the member Jae Seong.

Jae Seong first appeared on television through 'Super Star K' Season 2 back in 2010, as a young 13-year-old boy who made every judge swoon over his angelic voice. What's interesting here is that, while he was on the program, Oh My Girl's Seunghee was also a young contestant (she was 14 at the time), and the two ended up singing a duet with the song "Nagging" by IU and Seulong! (Check out the video below for the adorable moment.)

Jae Seong got eliminated after the show's 3rd round, but his luck did not end there. After the program, he got signed to Fantagio Entertainment, starting a brand new life as an idol trainee. There is actually a video of his audition for Fantagio, which you can take a look here. Below is a video uploaded by Fantagio, after he officially became their trainee through the company's pre-debut training program i-Teen. (The i-Teen program also used to include the agency's current idols such as Weki Meki and ASTRO). Jaeseong here is 16-years-old, singing an R&B version of "Venus" by Hello Venus when the girl group was still co-signed with both Fantagio and Pledis Entertainment.

A few years after this, Jaeseong remained in the company, going on to train with other fellow high-schoolers including the members of ASTRO. Under the i-Teen system, Jaeseong and the trainees who ultimately became ASTRO delivered live performances in venues such as Lotte World (an amusement park), giving them a chance to practice in front of real live audiences. Below are actually some very precious fancams of Jae Seong performing "Just A Feeling" by S.E.S., shot in the same frame with Moonbin, Sanha, and Rocky. 

In the end, for reasons yet undisclosed, Jae Seong did not go onto debut with ASTRO. So, when ASTRO had to perform this cover during their debut era, they actually had to create a new six-member version of it, which eventually made it to their web drama 'To Be Continued' and also on one of their 'Kiss The Radio' live performance of the song.

After leaving Fantagio (I'm assuming), Jaeseong then decided to go to Seoul Institute of the Arts as a music major, concentrating on commercial singing. There are a couple of videos in which he sings as part of his curriculum and also during some of the university events. Here is one of them below. 

Although we don't know how exactly he made the transition from being a normal university student to an artist under his current company, Jae Seong's pre-debut contents definitely prove his extensive amount of past training. Don't you wonder if he still keeps in touch with the ASTRO members, or even with Oh My Girl's Seunghee?

Stay tuned for Part 2 to read about the past experiences of the other two members of Class Mate: Seong Jeong and Byung Min! 

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