This book is an annotated edition of his work.

Rikuchū is a former place name in Japan, referring to a part of present-day Iwate Prefecture.

He used skywriting for his proposal.

There are many marginal notes on the pages of this book.

A block of small-sized text has been added at the bottom of this page.

Astronautics is a field of study related to the exploration of space and the design of spacecraft.

He is majoring in astronautics.

Mail arrived while I was away from home.

My father's hobby is breeding Ranchu.

My new pet is a ranchu.