The theme is the comparison between nature and man-made. This consists of the man-made such as ruler and gear, and natural objects such as leaves and weeds. In general, the word "nature" is used as the antonym of mankind. But I guess the true meaning of it is the state which nature and mankind harmonize.

Human and Nature

When I overview five pieces which were created from October 2017 to January 2018, I found all of those pieces were created following the same theme, "the relationship between mankind and nature.
The first piece, "touch", describes the interest in natural material. The second piece, "lesson", describes the warmth of the tool.
The third piece, "nature" describes the comparison between nature and man-made. The fourth piece "various aspects of me", describes the way of expression of me. Then, the last piece "coexist and harmony" describes the power of mankind who harmonize man-made with nature.