It is well-known that a growing number of foreigners have arrived to reside in Japan in the past decade, and one of the fastest growing populations is the Vietnamese. While many of them have come as technical trainees, they are not the only Vietnamese people in Japan. In fact, there are refugees who arrived in the last century during and after the Vietnam War, family members of the refugees who came recently, and also people who entered Japan as students and have stayed to work in the country. This paper introduces different cases of Vietnamese residents in Japan and shows their diversity. Each of the Vietnamese presented in this paper has his/her own backgrounds, lives under different situations, has his/her own problems peculiar to the situations, and has own values. The paper argues that not acknowledging this type of diversity is one of the major problems in Japanese discourse on foreign residents. Foreigners are often regarded as if they are all same, constituting one social group, rather than a group of diverse people. People often comment that growing number of foreigners might result in less secure society, or less jobs for the Japanese, but the diversity of the Vietnamese people presented in this paper shows that it is too simplistic to frame all Vietnamese people as “Vietnamese in Japan” or all foreign workers as “foreigners”, and that various social problems cannot be simply seen as “Japanese vs. foreigners.” Rather, the paper suggests, in the age when foreign residents are increasing rapidly and Japan is faced with the challenge of building a kyosei society in the real sense, that it is important to look at each different situation and act and solve problems according to the case.