This paper is a document of the lecture on 'Family System and Japanese Society' delivered at the University of Tokyo by one of the most famous sociologists, Kizaemon Aruga in 1954. These lecture notes were written down by Akiyoshi Takahashi who was a university student and attended Aruga's lecture at that time. It was a time just before Aruga was beginning to actively publish many articles after a long silence following WW Ⅱ . It was also a time just after a criticism by Seiichi Kitano had been offered which called into question on Aruga's understanding about the essence of the cognate relationship, which is a Japanese proper relationship among the stem family （honke in Japanese） and branch families （bunke in Japanese）. We can observe the real voice of Aruga with a feeling of tension based on his polemical statements in this lecture, which we cannot understand from his written articles. These lecture notes not only contain a documentary value on this dispute but also introduce us a deeper understanding about Aruga's theory.
In 2015, the United Nations adopted the ‘2030 Agenda for Sustainable Development’, including sustainable development goals（SDGs）. They succeeded in obtaining an agreement on the importance of sustainability as the principle of the earth community including the Global North. This paper aims at creating sustainability science of agriculture and rural community. First, this paper analyzes the development process of Sustainable Development concept that originated from the World Commission on Environment and Development. Second, this paper examines the characteristics of SDGs, namely （1） its comprehensiveness and absorption of even controversy matters, （2） parting from ‘trickle-down’ theory by highlighting individual person through announcement of ‘Leaving No One Left Behind’, （3） agreement from both the Global North and South, and（4） medium- and long-term scope for realizing sustainability. It is well known that agriculture holds sustainability in nature because it is based on the vitality of life. The important factors of realizing vitality of life include ‘cycle of being’ based on material cycle and diverse relations in ‘eco-tope.’ Thus, this paper also analyzes how sustainability has decreased in the modernization process. However, recently, sustainability in agriculture has been re-evaluated, as is shown by organic farming movement and eco-farming. Finally, this paper examines farming with creatures in Japan as a good example of sustainable agriculture. Based on its purpose, farming with creatures is categorized into three types: （1） branding and marketing strategy-oriented farming, （2） alternative agriculture in terms of technology transformation for the conservation of habitat and partial substitution of farm practice, and （3） gathering creatures as food and daily joys. Farming with creatures gives us a good clue to create sustainability science in agriculture and rural community.