DA PUMP. Apparently they are a real boyband which just happen to be written into the manga B.B.Explosion. Based on their music video Rapsody in Blue, they are quite likeable.
Their song, Rapsody in Blue, sounds familiar and fun. Their dance, the set, and their appearance remind me of both early Super Junior and David Tenant/Doctor Who at the same time. Check it out.
Therefore, this music video is happy happy happy and warm heart feelings. A veritable win for DA PUMP.