What happens to the Man on the Moon (Katsura-otoko) when it rains? And where does he go?

The man on the moon
No longer lives
On the moon when it rains

The man under the Katsura tree
No longer lives on the moon
When it rains

桂男すまずなりけり雨の月
Katsura-otoko sumazu nari keri ame no tsuki

Matsuo Basho, Iga, Mie province, Fall 1669

The Man on the Moon

Katsura-otoko, originally a Chinese myth that a man lives on the moon. He spends his days pruning the branches of a Katsura tree. The Katsura is similar to the Red Bud tree, a good shade tree, not large whose flowers appear in Spring before the leaves. Anyone who has ever pruned a Katsura, or a Red Bud, knows that the tree grows its branches back quickly. This explains the waxing and waning of the moon.

But it doesn’t explain where he goes.

It is likely that this haiku appeared in an anthology published in 1669 when Matsuo Basho had not taken on his pen name of Basho (Banana). Rather he was going by Tosei, meaning ‘unripe peach.’

Notes on Translation

Katsura (a flowering tree like a Red Bud) otoko (man) sumazu (does not live) nari keri (a story relating past events) ame no tsuki (literally rain of the moon)

In Chinese folklore, he is known as Wu Gang (吴刚), and he spends his time endlessly cutting down a tree growing on the moon.