Wu Chun
Derived from the definition of Fahrenheit, each of the four members represents a season or temperature that corresponds with their different personalities. Calvin Chen represents spring, warm; Jiro Wang represents summer, hot; Wu Chun represents autumn, cool; and lastly, Aaron Yan represents winter, cold. Each of the four members also has his respective temperature represented on the Fahrenheit scale: Calvin Chen is at 77 degrees, Jiro Wang is at 95 degrees, Wu Chun is at 59 degrees, and Aaron Yan is at 41 degrees. Each of their temperatures are separated by 18 degrees.