Planets and Days of the Week

People who watched the Sailor Moon, セーラームーン (se-ra-mu-n) will know that the characters can transform into Sailor Soldiers that fights against evil.  Each Sailor Soldiers are named after a planet of the Solar System and are able to use powers of the planets' element.  

Kanji	Hiragana	Romaji	English (Literal Meaning)
水星	すいせい	Suisei	Mercury (Water Star)
金星	きんせい	Kinsei	Venus (Gold Star)
地球	ちきゅう	Chikyuu	Earth (Earth Ball)
火星	かせい	Kasei	Mars (Fire Star)
木星	もくせい	Mokusei	Jupiter (Wooden Star)
土星	どせい	Dosei	Saturn (Earth/Soil Star)
天王星	てんのうせい	Tennoosei	Uranus (Heaven/Sky King Star)
海王星	かいおうせい	Kaioosei	Neptune (Sea King Star)
冥王星	めいおうせい	Meioosei	Pluto (Underworld King Star)

In the Japanese and Chinese language, the first five planets of the Solar System are named after the five elements of Water, Gold/Metal, Fire, Wood, and Earth, while the other three have names of kings, though the ninth, Pluto is not considered a planet anymore, but a dwarf planet. In addition to that, 王 or おう (ou) means King.  

Kanji	Hiragana	Romaji	English
水	すい / みず	Sui / Mizu	Water, Liquid, Fluid
金	きん /  かね	Kin / Kane	Gold, Metal
火	か / ひ	Ka / Hi	Fire, Light, Heat
木	もく /  き	Moku /  Ki	Tree, Wood
土	ど / つち	Do / Tsuchi	Earth, Soil, Ground
天王	てんのう	Tennou	Heaven + King
海王	かいおう	Kaiou	Sea + King
冥王	めいおう	Meiou	Underworld King

In the Solar System, there are also the Sun and Moon.  The Sun is 太陽 or たいよう (taiyou) and the Moon is 月 or つき (tsuki).  日 is another word that can mean the Sun when it's read asひ (hi), and when 日 is read as にち (nichi) it is a short form for Japan and also the suffix (-th).  月 can also be read as がつ (gatsu) which is a suffix for months of the year.

日in Sunday is also read as にち (nichi); Sunday, 日曜日 or にちようび (nichiyoubi).  月 can also be read as げつ (getsu) as in Monday, 月曜日 or げつようび (getsuyoubi).  The other days of the week are elements of planets.  The Korean days of the week have similar meanings as well.

Kanji	Hiragana	Romaji	English
日曜日	にちようび	Nichiyoubi	Sunday
月曜日	げつようび	Getsuyoubi	Monday
火曜日	かようび	Kayoubi	Tuesday
水曜日	すいようび	Suiyoubi	Wednesday
木曜日	もくようび	Mokuyoubi	Thursday
金曜日	きんようび	Kinyoubi	Friday
土曜日	どようび	Doyoubi	Saturday

Let’s learn how to say the month of the year and days in the month in the next post, and we will be able to tell what day is today, the date, and month in Japanese.