Sulfurina Ryuu-san
Summary
Sulfurina Ryuu-san personifies the Emerald Green Spring, a hazardous hot spring that releases a lethal mixture of hydrogen sulfide and sulfur dioxide. This location is crucial to the plot, as the group must navigate its deadly fumes to extract sulfuric acid from the water. They intend to use this chemical to synthesize aspirin, which is necessary to cure Ruri of her illness. To survive the environment, the characters utilize silver as a detection tool for hydrogen sulfide, allowing them to identify the pockets of poison gas and avoid them.
