BTOB, visual potential explodes... 'Spark' concept photo released

The concept photos for the pre-released song 'Bulssi' have been revealed :-)

As the song title suggests, the red lighting is impressive!

I'm curious about what the first project with the four members Eunkwang, Minhyuk, Hyunsik, and Peniel will be like.

It's said to be released on the 31st, so please watch it♥