A Second Mother(1972)

Original title: 둘째 어머니

Nam-Ok who has Yun-Ho and Yun-Suk remarries widowed Heung-Yeol who has Hyeong-Tae and Hyeong-Ja. Nam-Ok are concerned about frequent quarrels between half brothers and sisters, but manages to deal with them wisely. As Yun-Ho who went to fishing with him falls into the water, Heung-Yeol tries to save him only to drown himself to death. Fifteen years later, Hyeong-Tae goes abroad to study while Hyeong-Ja lives in extravagance in Seoul. Yun-Suk gets to know Dong-Oh on the train, and Dong-Ho gets to like her, but later misunderstands her due to Hyeong-Ja's scheme, which causes Yun-Suk to commit suicide.