A YouTuber by the name of Rodion Drozdov created a spiffy video bringing together the main cast of the anime "Hisone to Masotan"（ひそねとまそたん）from their dancing end credits and some spunky 80s dance music via Toshiki Kadomatsu（角松敏生）.
Drozdov already mentioned the source of the song in the comments, but I will identify it as well. It's "Step Into The Light", a track from Kadomatsu's 1984 album "After 5 Clash". Aside from all of the rapping and chorus work, it's an extended musical riff whose funkiness reminds me of The Dazz Band to a certain extent.
It may remind me of The Dazz Band but it isn't from The Dazz Band, and this is why I like to read the comments sometimes under a video. One never knows what kind of information can be gleaned. The uploader for the "Step Into The Light" video provided above and a commenter talked of the fact that Kadomatsu had gotten the basis for the song from a creation by an American R&B act known as Unique. The song is titled "What I Got Is What You Need" and it was released in 1983.
There was no mention of this point in the J-Wiki article for "After 5 Clash", but it did make it into the article for the band under "Legacy" at the bottom. The source was a page on "Japanese Soul" on which the author had made the comparison with a couple of videos (the "Step Into The Light" video has been taken down unfortunately).
In any case, joining Kadomatsu's funk here are Eiji Nakahara and Noriko Miyamoto（宮本典子）in the rapping portion. Kadomatsu, Yurie Kokubu（国分友里恵）and Keiko Toh provided the chorus.