Koupen-chan and the 24 Solar Terms (Seasonal Words)

Background

In traditional Chinese lunisolar calendars, the year is divided into 24 “solar terms,” which are significant periods or moments corresponding to a particular astronomical event and/or natural phenomenon. (Wikipedia)

Rurutea frequently posts about some of these key solar terms, particularly those aligning with the start of each season. They posted a thread back in 2018 with a post for every solar term, and this page compiles and translates them.

Wikipedia lists every solar term, and there are some websites that provide further cultural information. I will list the ones I referenced in the translation of these posts at the bottom, under “References”.

There is also an entire Koupen-chan book about seasonal words, including these solar terms: https://www.kadokawa.co.jp/product/322303001381/.

Translations

C: Koupen-chan and the 24 Solar Terms (Wikipedia)

(24 terms denoting the changing of the seasons)

Translations are below their respective images.

#1: The first day of spring (risshun), approx. Feb 4th

First day of spring (Wikipedia)

#2: Rain water (usui), approx. Feb 19th

Rain water (Wikipedia)

Koupen-chan: Oh, the snow is melting~

#3 “Awakening of Insects” (keichitsu), approx. March 6th

TN: This is the day when hibernating insects emerge from the ground.  (Jisho.org)

Rurutea: Spring draws closer with every rainfall, and this is around the time when the spring weather invites lively insect activity.

Koupen-chan: Oh my, who could that be…?

#4 "Spring Equinox" (shunbun), approx. March 20th

Rurutea: A refreshing breeze blows upon the sakura in full bloom.
Oh…?

Koupen-chan: hokekyo…!

Japanese Bush Warbler: ho– hokekyo

#5 "Clear and Bright" (seimei), approx. April 5th

Rurutea: This is the season of clear air, the green of new leaves, and profusely blooming flowers in various colors.

As for Koupen-chan, who loves flowers…

#6 "Grain Rain" (kokuu), approx. April 20th

Rurutea: The spring rain is a blessing to crops. When lots of indispensable rain pours down to develop grain rain, it becomes a good opportunity to sow seeds.

Seems like Adelie-san also planted some turnip seeds the other day…?

Adelie’s thought: Turnip

#7 "First Day of Summer" (rikka), approx. May 6th

Rurutea: This is around the time that vegetation grows greener in color, the wind that previously carried a chill becomes more comfortable, and living things start to become more active. It looks like Koupen-chan has discovered something on their walk.

#8 "Lesser Fullness of Grain" (shouman), approx. May 21st

Rurutea: The time of year to bask in the sun and when all living things grow rapidly.

Koupen-chan has found a flower that looks like it has a bunch of little bells attached to it…

Polar Bear-san: This is a Lily of the Valley (suzuran). It also goes by the name kimi-kage-sou.

Koupen-chan: It’s awfully cute…

TN: “Lesser fullness of grain” refers to the time when the seeds of grain start to become full but are not yet ripe.

References:
https://en.wikipedia.org/wiki/Xiaoman

https://www.ewccenter.com/xiaoman-lesser-fullness-of-grain/

#9 "Grain in Ear" (boushu), approx. June 6th

Rurutea: The “Awn” (nogi) is the part that protrudes from the tip of plants like rice, and it is said that “Grain in Ear” (boushu) is when the seeds of those plants are sown. Since it’s also the season when plum fruits turn yellow, it looks like Koupen-chan is being taught how to make plum juice.

Adelie-san: Thanks for helpin’ out!

Yokoshima Enaga: Ku ku ku… How easy

Koupen-chan: I’m so excited~

#10 "Summer Solstice" (geshi), approx. June 21-22

Rurutea: The summer solstice is the longest day in the year, and the shortest night.

Despite the time of night, you receive an invitation for a late-night snack.

Koupen-chan: Somehow it felt like daytime lasted a long time today!

Yokoshima Enaga: Would you like some lightly pickled radish, too?

#11 "Minor Heat" (shousho), approx. July 7th

Rurutea: The time of year when summer starts. It looks like Koupen-chan is in the midst of preparing Tanabata decorations.

Koupen-chan: You write one too!

Blue paper: You!
Red paper: Evil!

TN: About Tanabata: https://en.wikipedia.org/wiki/Tanabata

#12 "Major Heat" (taisho), approx. July 23rd

Rurutea: Even though it feels boiling hot, Koupen-chan and Yokoshima Enaga-san have a bit of refreshing coolness…?

#13 "First Day of Autumn" (risshuu), approx. August 8th

Rurutea: According to the calendar, we reach the first day of autumn while the sun shines glaringly bright. It is said that the word fall (秋 aki) originates from phrases such as, “the harvest is overflowing” (shuukaku ga aki michiru) or “the sky is clear and bright” (sora ga seimei [akiraka]).

Since the heat is expected to continue for a while longer, please take good care of yourselves 🎐

Koupen-chan: You’re doing a great job even though it’s hot every day!

Yokoshima Enaga: Flap flap!

#14 "Limit of Heat" (shosho), approx. August 23rd

Rurutea: The sky grows clear and high, and the wind takes on an invigorating quality. It looks like Koupen-chan has something to show you…?

Koupen-chan: Look! A dragonfly! It’s so cool!

#15 White Dew" (hakuro), approx. September 8th

Rurutea: When the temperature difference between day and night grows large, dew forms in the morning and evening, and it is said that the people of eld called this dew “White Dew.”

#16 "Autumn Equinox" (shuubun), approx. September 23rd to 24th

Rurutea: Like the vernal equinox, the autumn equinox is when day and night become the same length. This day is the turning point where the sun weakens, gradually bringing us closer to winter.

Koupen-chan: Wanna relax?

#17 "Cold Dew" (kanro), approx. October 8th

Rurutea: We get deeper and deeper into autumn, and natural landscapes become abundant with color.

It seems Koupen-chan and Yokoshima Enaga-san have come to search for something together…?

Yokoshima Enaga: We found a ton!

Koupen-chan: It’s true! We found sooo many!

TN: I believe they’re collecting acorns.

#18 "Frost Descent" (soukou), approx. October 23rd

Rurutea: This is around the time the dew that forms in the morning and evening turns into frost.

It appears that Koupen-chan is engrossed with persimmons.

Yokoshima Enaga: Ku ku ku… Persimmon!

Koupen-chan: Persi-persimmon!

#19 "First Day of Winter" (rittou), approx. November 8th

Rurutea: This is around the time the mountain trees, whose colors had brightened with the seasons, grow dull and shed their leaves, piling them upon the ground.

According to the calendar, this is the start of winter.

Adelie-san: Hey, why dontcha have one

Koupen-chan: puff puff

#20 "Minor Snow" (shousetsu), approx. November 22nd

Rurutea: As we get further into winter, it grows colder and the rain starts transforming into snow.

Speaking of Koupen-chan …

Koupen-chan: It’s so toasty… (po– poi)

Yokoshima Enaga: (Toasty…?)

#21 "Major Snow" (daisetsu), approx. December 7th

Rurutea: This is the time when the trees lose their leaves and snow falls. The cold becomes severe.

(My update is a bit late. I’m sorry 💦)

Koupen-chan: Oh my~

#22 "Winter Solstice" (touji), approx. December 21st to 22nd

Rurutea: This is the shortest day of the year. Koupen-chan and their friends warm up in a yuzu (citron) bath!

Koupen-chan: It’s awfully toasty… (po– poi)

Yokoshima Enaga: (Toasty…?)

#23 "Minor Cold" (shoukan), approx. January 6th

Rurutea:  “Minor cold” means the cold has not reached its peak. Koupen-chan and Yokoshima Enaga-san seem to be absorbed in playing in the snow.

#24 "Major Cold" (daikan), approx. January 20th

Rurutea: The cold is severe, but you can just barely start to see the signs of spring at this time.

Koupen-chan and their friends are relaxing by the heater…

This marks the end of Koupen-chan’s 24 Solar Terms series!

Thank you very much for joining me 🍀

References

The various references I found while researching some of the solar terms.

Note Wikipedia uses the romanized Chinese names of the solar terms.

https://en.wikipedia.org/wiki/Solar_term

“First Day of Spring” or Risshun: https://en.wikipedia.org/wiki/Lichun

Rain Water or Usui: https://en.wikipedia.org/wiki/Yushui_(solar_term) 

https://eng.qchm.edu.cn/2018/0628/c4642a38772/page.htm

Spring Equinox: https://en.wikipedia.org/wiki/Chunfen

Japanese bush warbler (cry reference): https://en.wikipedia.org/wiki/Japanese_bush_warbler

“Clear and bright” or seimei: https://en.wikipedia.org/wiki/Qingming_(solar_term)

“Grain Rain” or kokuu: https://en.wikipedia.org/wiki/Guyu 

“Traditionally, Guyu marks the beginning of warmer temperatures and the onset of the rainy season, making it an important period for farmers to ensure a satisfactory harvest for the rest of the year.”

First day of summer (approx. May 6th) (rikka): https://en.wikipedia.org/wiki/Lixia

“Lesser Fullness of Grain” / “Grain full” Approx. May 21st

https://en.wikipedia.org/wiki/Xiaoman 

https://www.ewccenter.com/xiaoman-lesser-fullness-of-grain/

“Grain in Ear” approx. June 6th, when awns start to grow on grains (Jisho)

https://en.wikipedia.org/wiki/Mangzhong

https://www.ewccenter.com/mangzhong-chinas-9th-solar-term/ 

“Mangzhong in Chinese means that the wheat with awns are ready to harvest, and the rice with awns are to be planted.” (EWC Center)

Original Tweet Thread

This is a 24-post thread, please click to see all 24.

コウペンちゃんと二十四節気
０１「立春（りっしゅん）」 pic.twitter.com/QbNygg7yXn

— るるてあ (@k_r_r_l_l_) February 4, 2018

Other Season-Related Tweets

教えてくれるタイプのシロクマさん pic.twitter.com/RDyzlqi7Ts

— るるてあ (@k_r_r_l_l_) August 21, 2024

教えてくれるタイプのシロクマさん pic.twitter.com/QegtSWHZLz

— るるてあ (@k_r_r_l_l_) February 3, 2025

C: The Turning of Seasons

[Dialogue is in alt text attached to images] https://t.co/5vB5S7PZGP pic.twitter.com/Nju8eg7Zh6

— kou~pen~chan!! (translations/翻訳) (@koupenchan_yaku) August 21, 2023

Correction: I misread the word and 二十四節気 is actually nijuushi-sekki, not setsuki. You know.. the small っ vs normal つ.

Here's the corrected image: pic.twitter.com/45rwl3uaak

— kou~pen~chan!! (translations/翻訳) (@koupenchan_yaku) August 21, 2023

C: The First Day of Spring (~Feb 4th)*

1. P: Today is the first day of spring. Slowly but surely, more signs of spring will start to appear.
K: Oh~

2. Both: You made it through winter, amazing!
P: However, the start of spring is when cold temperatures peak, so stay warm, okay~ https://t.co/9xr4o9lFQQ

— kou~pen~chan!! (translations/翻訳) (@koupenchan_yaku) February 8, 2024

C: Polar Bear-san who's the type to teach you

P: Today marks the "first day of spring"*. It's still cold, but it's that time when the plum blossoms start to bloom, and we can feel the first signs of spring.

TN: This is according to the lunisolar calendar and is approx. Feb 4th. https://t.co/XSvdc5vSEe

— kou~pen~chan!! (translations/翻訳) (@koupenchan_yaku) February 3, 2025