On November 21, 1963, the evening before President John F. Kennedy was assassinated, Tsu's only appearance on Perry Mason was aired on CBS, as she played the role of defendant Juli Eng in "The Case of the Floating Stones." She made guest appearances on most of the other popular '60s-70s television shows such as I Spy, The Man From U.N.C.L.E., Voyage to the Bottom of the Sea, Family Affair, Mission: Impossible, and The Wild Wild West. She was tested for, but didn't get the female lead of The Sand Pebbles.