Written Japanese was developed and refined after Japan began using Chinese kanji characters in the early 5th century. This history is reflected in the many words related to kaku, or "to write."

This episode focuses on words related to yama (mountains). Mountains make up about 75% of Japan's territory, and they have made their way into many common expressions in the Japanese language.

This episode focuses on me (eye). Just like other languages, Japanese has a lot of words and phrases related to eyes, and they are often used in daily life.

This episode focuses on words related to fukuro (bag). Reflecting its unique wrapping culture, Japan has a wide variety of bags, leading to an equal variety of Japanese words and expressions.

This episode focuses on words related to shio, or salt. Salt played an important role in the development of Japan's food culture and religion, and it continues to add flavor to many Japanese expressions.

In this episode, poet and literary translator Peter MacMillan explores Himeji Castle in Hyogo Prefecture and examines words and expressions related to Japanese castles.