INOUE, Seigetsu (1822?-1887) is a legendary bleaching haiku-poet in Japan.

 

'わらじwaraji' or straw sandal is old style Japanese sandal.

 

 This haiku is very simple and it says just only like ''They're 

strongly wet in the spring rain'', but we also can read his joy for the change of seasons from winter to spring.

 If he was caught in the rain or snow in winter, he and his feet couldn't stand in the cold. But now the spring has come and he didin't mind his feet to get wet. He might feel free to walk around outside, better than in winter

 So on this haiku,  we can imagine that he would find the joy of the spring to feel the moistness of straw sandals easily.