77Danui Bimil
Japanese title: 77단의 비밀
Alternative titles: 77 Group's Secret, Secret of 77 Dan
Type: Movie
Source: Radio
Episodes: 1
Status: Finished Airing
Aired: Jul 23, 1978
Duration: 1 hr 9 min
Rating: G - All Ages
Producers: Samdo Film
Genres: Action, Adventure, Drama

Sang-ho and Sun-ja are kidnapped by someone and live in brutal abuse while performing acrobatics in a circus troupe called the "77th Dan". 

One day their uncle comes to visit them and they try to escape, but when Sun-ja is captured by the circus, a black hooded person, the object of Japanese fear, suddenly appears to help them...

(Source: Daum; translated)