Chapter 1 - Life Lessons

① A blessing in disguise
② Turning misfortune into blessing
③ Nine narrow escapes
④ Carving a boat and seeking a sword
⑤ Deliberation
⑥ Self-employment
⑦ Cause and effect
⑧ Great longevity
⑨ Reform
⑩ Return to private affairs
⑪ Thousands of hardships
⑫ Gojingamrae (苦盡甘來)
⑬ Seven battles and eight battles
⑭ A Spring Dream
- Four-character idiom Sudoku

Chapter 2 - Human Relationships

① Mutual assistance
② Sharing joys and sorrows
③ Repaying kindness by tying up grass
④ Sacrificing one's life to become a benevolent person
⑤ A thief returns with a stick
⑥ The sweet talk theory
⑦ The importance of love
⑧ Soft on the outside, strong on the inside
⑨ Childhood friend
⑩ Between dog and monkey
⑪ Similar species
- Idiom Quiz Room

Chapter 3 - Success and Failure

① Morning reading at night
② The achievements of Hyeongseoljigong (螢雪之功)
③ Cheongchuleoram (靑出於藍)
④ Self-made man
⑤ 100 wins in 100 battles
⑥ Point-in-place view
⑦ Dragon's head and snake's tail
⑧ Too much is as bad as not enough
⑨ Song on all sides
⑩ In the fog
⑪ Right and left
- 〈Success vs. Failure Idiom Song〉

Chapter 4 - Nature and Animals

① Family escort
② A stone from another mountain
③ Three in the morning and four in the evening
④ Cooking a dead dog
⑤ Fisherman's profit
⑥ Hwa-ryong-jeom-jeong (?Dragon dotting the eyes)
⑦ Crane's head is waiting patiently
⑧ The icing on the cake
⑨ Reading the sutra with an ox's ear
⑩ Killing two birds with one stone
⑪ Adding frost to the snow
- 〈Holy Moly Idiom Song〉

Chapter 5 - Learn More

① Sipping sweet and spitting bitter
② Chimsobongdae (針小棒大)
③ Hamheung envoy
④ Seeing things alive
⑤ Different people say the same thing
⑥ East question, West answer
⑦ Half-belief, half-doubt
⑧ Right and wrong
⑨ A reputation that lives up to its reputation
- 〈Idiom Version Mint Choco Song〉

Red Underwear Yakko's common sense series, chosen by 1.19 million subscribers! This time, it's four-character idioms!
Even the Chinese idiom is true to its name, but it is different when it is said by Yako in red underwear.

1) Even difficult idioms are a sure win with Red Underwear Yakko!
Idioms that come naturally when you laugh out loud

Enjoy the original episodes of 'Red Underwear Yako' that have captivated 1.19 million subscribers, as well as the special episodes that can only be found in 'Red Underwear Yako Children's Common Sense 2', and feel the natural usage of four-character idioms.

2) Not only are there four-character idioms frequently used in daily life, but there are also four-character idioms related to elementary school curriculum. This is the icing on the cake?! A game that can only be played in the world of Red Underwear Yako, killing two birds with one stone!

The book contains four-character idioms frequently used in daily life and four-character idioms related to elementary school curriculum.
Master your four-character idioms with this fun game that captures the unique world of Red Underwear Yako.

3) As expected! The song with the highest number of views, 13 million views, is called Yakko.
If you keep humming the four-character idiom, it will soon stick in your head!

If you hum along to the four-character idioms in songs that have received much love on the Red Underwear Yakko channel, such as “Mint Choco Song,” “Holly Molly Guacamole Song,” and “Pat-bung VS Shu-bung,” which have reached a peak of 13 million views, the four-character idioms will remain in your head for a long time before you know it.