Research on android robots, which are made to thoroughly resemble humans, has made significant progress in the past 10 years. One of the latest android research probes into the characteristics that make us perceive humans as humans. The most advanced robots are made by paying attention to details. They not only have human-like appearance, but also make subtle movements in the eyes and neck. On the other hand, people around the world are opening up their hearts to robots with no facial expressions, but can talk like humans. We will focus on android research to delve into the big question, "What makes us human?"