Jang Youn

Former intelligence agency agent Min Ki-heon (played by Gong Yoo), who is on the verge of death, happens to meet Seo Bok (played by Park Bo-gum), the "immortal" who holds the secret to human immortality. Min Ki-heon's last mission is to protect Seo Bok to a safe place at all costs. Along the way, a huge financial group and various evil forces that want to possess the immortal launch a large-scale hunt

Shang Wan (played by Cha Tae-hyun), a down-and-out young man with no hope for life, has attempted suicide several times but failed. After being rescued and waking up recently, he found that he could actually see ghosts. "Uncle Smoker" (played by Ko Chang-seok), "Crying Auntie" (played by Jang Young-nam), "Perverted Grandpa" and "Foodie Kid" all came uninvited to stick to Shang Wan and Ying Ying