Microorganisms are said to be the earliest existing lifeforms on Earth, and a vital part of maintaining its ecosystems. However, because of the difficulty in identifying their function due to their microscopic size, less than 10% of microorganisms have been named and identified. Microbial ecologist Dr. Yusuke OKAZAKI is performing research on the waters of Lake Biwa, where a C-shaped bacteria known as CL500-11 appears at especially high concentrations in its depths. To solve its mysteries, he must succeed in the difficult task of isolating it from other bacteria found in the lake, and growing it separately. In addition, he uses a new method called metagenomic analysis to gain a greater understanding of the lake's ecosystem as a whole.