Probably some of my old students and friends back in Japan taking a look at the above Pocari Sweat ad and hearing the song will go "Natsukashii na...".
But I remember the music video for Sentimental Bus' "Sunny Day Sunday" since it got a ton of airplay on the various stations. This band didn't have a long shelf life (1996-2000), but it certainly got its 15 minutes of fame through their 4th single which came out in August 1999. The name of the band itself was worthy of engrammatic storage but watching them in the video jumping all over the place in a garage with a Brillo-headed Natsuyo Akabane（赤羽奈津代） on vocals ensured lasting remembrances for those who were in high school at the turn of the century. That rat-a-tat drumming and the grrrrlish delivery by Akabane has kept it in the 1999 file of my brain.
Akabane took care of the lyrics while keyboardist and co-member Akinori Suzuki（鈴木秋則） handled the music side of things. "Sunny Day Sunday" peaked at No. 4 and was the 39th-ranked song of the year. Even now, it's often used as a rallying song for high school baseball teams.