BTOB members Seo Eunkwang and Lee Minhyuk are active with solo projects, as Eunkwang unveils concept images and a motion teaser for his new single album 'OUR YOUTH', while Minhyuk releases a gritty visualizer for his track 'KO'. Meanwhile, former member Jung Ilhoon surprises fans with a surprise concert, and Peniel drops a digital single titled 'IDKI' with a lyric video.