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With each set of Kanji that you learn, it will feel like you've become even less blind when looking at Japanese text. Some of the characters in this lesson have a lot of readings, and you're not expected to get them all down now, but you do need to be aware of that they exist. 

The top of this character is 穴 (hole), which is on top of 工 (construction). The 工 gives the sound of the character, but it is also re-enforces the concept of opening for construction opens a whole new world of man's architecture.

The modern meaning of "sky" is an extension on previous meanings because it would seem more obvious to think that there is some roof over a hole that has been dug. If you think about how old these basic characters are (as old as 6,000 years), you shouldn't be surprised that this would be a representation of early human dwellings, and similar structures still exist throughout Southeast Asia.

But, with the fact that there is still this concept of "opening", if there is open space but the space is contained, this would mean the space is "empty". This "emptiness" can lead to being used for contexts such as vanity, hollowness, and so on. However, the most important meaning "sky" came about from the fact that the central vaulted area in these early dwellings was extended to the sky. 

音よみ: クウ
くんよみ: そら, から, あ（く・ける）, す（く), うつ（ろ）, むな（しい）, うろ ▽, あだ ▽

There are a lot of くんよみ, and as you can imagine, they hone down on specific meanings of 空 discussed above. そら is the word for sky. から mean empty, and the best word to remember this is 空手 because many of you already know that karate means empty hand.

あ（く） is a verb that has various means related to being "open/empty/vacant". あ（ける） is the transitive version of this verb, which means it would be used in contexts like "to empty something".

す（く） is similar and usually limited to expressions like being hungry. うつ（ろ） is an adjective that means "blank/vague". むな（しい） is an adjective that means "empty/in vain". うろ is a cavity in a something like a tree. Lastly, あだ is an adjective meaning "frivolous/vain", but this is pretty uncommon.

The character derives from a pictograph of the stems of small bamboo with poky leaves, and it eventually got expanded to refer to bamboo in general.

音よみ: チク
くんよみ: たけ

This comes from a pictograph of a heart, unlike ♥. When in other characters, it usually looks like the left side of 快 (pleasant). 

音よみ:  シン
くんよみ: こころ、うら ▽

  こころ refers to one's heart in an emotional sense. The physical/medical word for heart is in the word bank below. 

気 used to be written as 氣 and is composed of 气 (vapor) and 米 (rice). This character means "spirit", but it's far more different than anything in English. This word happens to be used in hundreds and hundreds of idioms that you will learn over the course of your Japanese studies. This 'spiritual' force can refer to the source of one's life/vitality/consciousness/temperament/feeling/interest. 

However, in compounds it can refer more explicitly to vapor related things such as gas and breath. 

音よみ: キ、ケ

This character used to be written like 二, but the upper stroke was as long and in the same location as the modern character, and the vertical line was added so that it would no longer be confused with 二. It's a good thing because students already have a hard time distinguishing 二 and ニ (ni in Katakana) from each other. 

This character means "above/up/top", and it sadly has a lot of readings that are for the most part all used rather frequently. 

音よみ: ジョウ, ショウ ▽
くんよみ: うえ, うわ-, かみ, あ（がる・げる), のぼ（る）

This character once looked like 三 without the last line. It means down/below/under, but it is extremely difficult to know how to read because it has so many readings. You almost have to take each word at a time, and it's unluckily one of those characters that utilize all readings to a decent extent. Furthermore, you have to address exceptions and alternative readings in words meaning different things.  

音よみ: カ, ゲ
くんよみ: した, しも, もと, さ（がる・げる）, くだ（る・す）, お（りる・ろす),  

This comes from a pictograph of a dog, and obviously millennia of years have done a number on it. 

オンヨミ: ケン
くんよみ: いぬ

Note: いぬ in a derogatory and wild sense can be written as 狗; when referring to the Zodiac of the Dog, use the character 戌.  

This character used to more clearly show a form of moon with a variant of 亦 (again). The character means night.

音よみ: ヤ
くんよみ: よる, よ 

朝 used to be , and if you were to go back in time far enough, you would see that the right-hand side is actually not a moon, but it's a representation of a river. This gave meanings that would eventually be retained in 潮 to mean "tide", adding water for clarity as the right-hand radical did become interpreted as the moon later on, which lead to its use to refer to the Imperial Court.

              This character, though, typically means day because people speculated in ancient times that the sun and moon were the sources of light, and if you look closely in the left-hand part of it, you'll see that sun 日 is springing through plants, which you typically see connected horizontally but in this case is bifurcated vertically by another radical. 

音よみ: チョウ
くんよみ: あさ 

This comes from a pictograph of a horse, but it may help to think of it as a carriage with the four dots as horse feet.

音よみ: バ
くんよみ: うま, ま, め

The くんよみ actually ultimately come from Chinese, and this has only been realized nowadays. 

This character comes from the pictograph of a cow's head with horns. This is cow. Muu!

音よみ: ギュウ
くんよみ: うし 

The roof and the top horizontal line represents some sort of covering element, and below is 土 (ground) plus dots meant to represent golden nuggets. This character, then, as you can imagine means "gold", but it has also been widened in meaning to mean money and metal in general. After gold is the money that most people would rather have, and it is a metal. 

音よみ: キン, コン
くんよみ: かね, かな-

The latter 音よみ is not as common.