In the early days of my time teaching in the Tokyo area, my teaching schedule was askew in that my weekends were Mondays and Tuesdays. The old NOVA school empire definitely made a regular Saturday and Sunday something to be preciously earned over many years...something that didn't sit well with me initially at least. However, there were some advantages in that visiting the various sightseeing sites and restaurants of Tokyo were much less crowded although my social life (such as it was) was slightly cramped when it came to going out with friends on Saturdays and Sundays since I couldn't stay out long at all.
However, I could be more leisurely about things on those Mondays and Tuesdays and there was a certain feeling of satisfaction that while everyone else had to rush out to work on Blue Monday, I was able to sleep in a bit more although for me, sleeping in meant waking up at 8 am. Often after the news was over at that time on Fuji-TV, I ended up watching the program that followed immediately afterwards which was the kid program Ponkikies（ポンキッキーズ）. That show could only have been geared for the kindergarten set since I couldn't imagine any kids older than 5 in Japan still staying at home at that time. But in any case, it was amusing to watch some of the antics of the characters and the music segments, one of which often included the kids' singing & dancing group, Folder.
This group of seven kids was launched from the Okinawa Actors' School, following in the footsteps of Namie Amuro（安室奈美恵）and SPEED. And it consisted of 5 girls and 2 boys of elementary and junior high school age: DAICHI, AKINA, ARISA, HIKARI, NATSU, MOE and JOE (the capital letters were their idea, not mine).
Debuting officially in August 1997 with "Parachuter", I have to say that this pint-sized engine of song & dance could cut quite the rug (my generation's equivalent of "bust a move") and the song created by Kazuko Kobayashi and Minoru Komorita（小林和子・小森田実）is quite catchy. The background vocals made me wonder if either Toshinobu Kubota or Keizo Nakanishi had a hand in the song's production but that didn't seem to be the case.
The single also made it onto Folder's first album "The Earth" which came out in November 1998. I couldn't find out in either the single or the album's case whether they were successful on Oricon but I'm fairly sure from their television exposure that they had a goodly amount of attention.
As Folder, the unit released a total of 7 singles and 2 albums between 1997 and 2000 before the two boys, JOE and DAICHI, left the group leaving just the 5 girls to keep going for a few more years as Folder5. Marcos V. has already written about one of their songs, "Final Fun-Boy" from 2001. Folder5 then folded (oops, sorry) in 2003.
According to J-Wiki, most of Folder have gone on to bigger and better things such as becoming solo singers and choreographers in their own right. But the most famous member has been HIKARI, or as she is known now, actress Hikari Mitsushima（満島ひかり）who is now showing on TV screens on TV Japan on Monday nights portraying the real-life over-the-top actress/host Tetsuko Kuroyanagi in "Totto Terebi"（トットてれび...Totto TV）on NHK.