Mr. and Mrs. Ho are longing for a grandson. Their son, Ho Chieh and daughter-in-law, Wan Ping, come home from abroad. Wan Ching, the little sister-in-law, is a nurse and comes with Mrs. Ho to meet her sister. At the airport, old Mrs. Ho mistakenly hears that her daughter-in-law is pregnant. After that, Ho Chieh has to attend a business party. However, his wife is not free for it so he begs his little sister-in-law to go as his wife. Wan Ching turns out to be a hit with the guests. In order to please his mother, Chieh asks little sister-in-law to take Wan Ping to the hospital for a pregnancy test and get a false positive report. But through a mistake, Wan Ping gets the report of a sterile woman. She is saddened by it but everyone lies to the old people in order to spare them the disappointment...
Unfortunately the movie Little Sister-in-law is not yet available on HBO Max.
| Sound | Tso Hong Yuan | Songs |
| Production | Lo Wei | Producer |
| Directing | Su Yang | Director |
| Production | Hsu Li-Hwa | Associate Producer |
| Writing | Su Kuang-hsun | Screenplay |
| Sound | Frankie Chan Fan-Kei | Music |
| Camera | Lin Tzu-jung | Director of Photography |
| Directing | Yang Che | Assistant Director |
| Editing | Lee Yim-Hoi | Editor |