If somebody asked me to choose between the sun and the moon as a place to live, I would choose the moon. In my mind, there are highways with 10 lanes on the sun, but the moon has alleys and narrow streets I can explore on foot. For me, the sun is a destination, but the moon is a gateway and a peep-hole to an unknown world.
As you may know, Japanese saijiki categorise the word ‘moon’ by itself as an autumn kigo and you will find many ways to say ‘moon’ in Japanese saijiki. For example, the full moon may be called gyokukon (round soul) or sasaraeotoko (small but lovely man – a nickname for the moon).
In Japan, there is a long tradition of admiring a full moon on the fifteenth day of lunar August. Special dishes of taro and sweet dumplings are prepared and pampas grass is arranged in a vase.
kono tsuki o imachi nemachi to yubi o ori
should this moon be waited for
by sitting or lying down …?
I calculate with my fingers
Sujyu Takano 
Sujyu Takano (1893-1976) is referring to a belief in ancient time that just before moonrise, three gods would come to show people a way to the Land of Paradise. The seventeenth-day moon which rises about 7pm is called tachimachizuki (the moon you wait for by standing). I can see my ancestor waiting for the moonrise near his gate after an evening stroll. On the eighteenth day, the moon rises about 30 minutes later than the previous day. Without electricity, the streets must have been dark by then. People waited in their living rooms or on their verandahs for the moon to rise. A kigo for the eighteenth day moon is imachizuki (the moon you wait for by sitting). The next day the moon does not rise before 8pm. In their bedrolls, people waited for the nineteenth day moon called nemachizuki (the moon you wait for by lying down).
During the Edo Period (1603~1867), a day was divided into 12 segments and each segment had the name of an animal. Those animals were the same 12 zodiac signs you see in a Chinese calendar. I have to admit that I do not know a kigo like ‘nakazuki in English. A character for ‘i’ (pronounced as ‘i’ in ‘inside’) means ‘boar’ and naka means ‘between’. In the modern world, the Hour of Boar is between 9pm and 11pm. I translated inakazuki (the moon rises between 9pm and 11pm) to ‘twentieth-night moon’ in the haiku below.
basu roubu no tora hoeteiru inakazuki
a tiger on his bath robe
Fay Aoyagi 
Inakazuki is a rather technical term which exists only in the haiku world or in a historical novel. This kigo is fascinating, but today I may need to explain inakazuki to a Japanese friend who does not write haiku. Saijiki are a treasure vault of kigo and sample haiku and I rely heavily on saijiki when I write haiku both in Japanese and English.
negaerishi ko wa gekkô ni chikazukinu
turning in sleep
my child is getting closer
to the moonlight
Yasuko Tsushima 
This is one of my favourite haiku written by Yasuko Tsushima. I may have completely misinterpreted the meaning, but let me tell you why I am intrigued with this haiku.
A sleeping face is peaceful and beautiful in the moonlight coming through a window. Watching him/her, a poet experiences the happiness which only a mother can enjoy. Yet at the same time, an invisible hand draws the child closer to the world we human beings do not belong to. Something wicked and strong pulls at the cord between mother and child.
My interpretation may be influenced with a legend of Kaguyahime, a story of the Moon Princess. A beautiful baby was found and raised by an elderly couple. Eventually, though, she returned to the moon on the fifteenth night (full moon) of lunar August when she declined to choose a husband.
kangekkô onore no hone mo sukitôru
winter moon light
my bones, too,
Yukiko Itoyama 
Sunlight helps me understand the shape of an object. A moonbeam shows me the inside of it.
I like moon-related kigo because I can lead a reader into a labyrinth. I may lose him/her in a maze. But I hope I am showing a way to the deep inner world.
American Indians and colonial Americans have a lot of evocative names for a moon. Lizard Cut Moon (January), Fish Moon (March), Buck Moon (July) and Leaf Fall Moon (October) are among many. Those names are more to describe a month than the moon itself, but they can be interesting kigo.
gesshoku matsu kawa e jyusshi o hirakiite
I wait for a lunar eclipse
with all my ten fingers spread out
to the river
Toru Sudo 
Technically speaking, gesshoku (lunar eclipse) is not a kigo. I found this haiku in the section of zô’(‘miscellaneous’ or ‘non-season’) in one of my saijiki.
In this haiku, moonlight still shines between the poet’s fingers and may shimmer on the river surface. But soon the Earth will move between the sun and the moon. Most of the time, we are under the influence of the sun or the moon. Can we be the absolute master of our life for the duration of the lunar eclipse?
itoshimeba ki mo katarikuru haru no tsuki
if I show my tenderness of love
a tree, too, will start talking —
Heinosuke Gosho 
Though I respect a long tradition of moon-admiring in the autumn, I am attracted to the moon in the spring. Spring is a budding season. The night air is filled with fragrance of flowers. Animals mate. The moon floats in the mist.
One of my Japanese friends told me that she did not understand how people write haiku in English. According to her, Japanese culture, including haiku, is very subtle. She said Japanese is a more ambiguous language than English; it is a more suitable language to express feelings. Writing in Japanese, a poet can avoid too much explicitness. I am not sure I totally agree. I think English haiku can be very suggestive, as well.
summer moon —
shadows with tiny horns
at the monkey bars
Fay Aoyagi 
My friend may say, “well, I can see that it is possible to compose a weird haiku in English. But is this a haiku or a 3-line poem?”
If I write a three-line poem, the above haiku may go like:
When I was looking for my lost childhood in the summer moonlight,
I saw shadows with tiny horns at the monkey bars.
I might be one of those with horns, here in my adopted land.
Haiku is a poetry form which requires reading between the lines. I strongly believe that we can achieve subtlety in English.
1: Haiku Saijiki edited by Fusei Tomiyasu, Kenkichi Yamamoto et al, Heibonsha, Tokyo, 1971.
2 : Ten’I (Ten’I haiku group members’ magazine), February 2003.
3: Tsushima Yasuko Shu (collection of work by Yasuko Tsushima), Yu Shorin, Tokyo, 2003.
4: Gendai Saijiki (Modern Saijiki), edited by Tota Kaneko, Momoko Kuroda, Ban’ya Natsuishi, Seisei Shuppan, Tokyo, 1997.
5: Dai Saijiki (Comprehensive Saijiki) edited by Shuoshi Mizuhara et al, Kodansha, Tokyo, 1982.
6 In Borrowed Shoes by Fay Aoyagi, Blue Willow Press, 2006.
All translation from the Japanese by Fay Aoyagi.