The first song happens to be my favourite from this amazing singer, and the dancers are from TreeTop, which is a large and very popular dancing group, with a lot of members. And I mean a lot.
If I had issue finding information about Frenzy 프렌지 a few posts ago, it's a near impossible job to find anything about this singer. There is a little entry about him here which mentions that Da-Little is also known as Hiradon/ひらどん/hrdn, has a twitter, and is now the singer for the band Sputnik, signed under the label of Nextfarm, whose offical website has a PV on the main page, with several others if you take a look around and downloads to some of their songs. From what I've found, Sputnik is a rather happy, dancing, typical Jpop band... But I really feel it doesn't promote Da-Little's voice enough, as it often uses autotune which is desperately not needed. They are however, an interesting band and I really wish the best for them.