“Friends” will give a real look into the cast’s daily lives and also show how they develop friendships and romance. It will feature “Heart Signal 2” cast members including Oh Young Joo, Jung Jae Ho, Kim Do Kyun, and Kim Jang Mi along with “Heart Signal 3” cast members including Lee Ga Heun, Park Ji Hyun, Seo Min Jae, and Jung Eui Dong.