Wells up in My Heart 1982 on netflix

A new secretary for the Hsiao family met an office boy on her first day at work. She was puzzled when he asked if she would marry into Hsiao family. Upon understanding the fact that all the Hsiao secretaries had married the Hsiao sons, she assertively assured that she would not follow the trend, they started dating and soon fall in love. Then one day an angry man stormed into the office and revealed the true identity of the office boy. He was actually the youngest son of the Hsiao family…