Yoo Chang Hyun, better known by his stage name Ricky, is the vocalist and lead dancer of the boy group Teen Top. He is also a model and actor. He is the brother of E:PSILON (Yoo Young Jin) from Alphabat. He appeared in Seo Tai Ji's video for the song ''Human Dream''. He has a talent for mathematics and for playing the piano. He enlisted on January 18, 2021 in the military. Watch drama online for free.