A Goat On a Boat to Float: The Case Diary of Chinami Chiba

By Takafumi Takada

Chinami Chiba, a young genius, and his friends witnessed a purse-snatching at a tourist spot. They decided to chase the thief to catch him. They thought they trapped the thief, when they drove him into the shore of a river, which was too wide to swim across.

The thief narrowly escaped the tight spot by using a large boat. The chasers had to use a small boat (holding up to only two passengers) to catch up on the runaway thief. To make matters worse, some of the chasers did not want to go on board with certain specific others. How do they have to plan the passenger combinations of the boat boarding and the sequence of the round trips between the two opposing shores, to get all of them to the other shore and continue the pursuit?

The so-called "river crossing puzzle", a famous logic puzzle, is ideally harmonized with the mystery fiction by Takafumi Takada, a popular mystery writer in Japan. The author is challenging the reader, namely YOU, to solve the brain twister.

This work was first published in 2002 by Kodansha and translated in 2015 for The BBB: Breakthrough Bandwagon Books.

• Language: English
• Publisher: Lulu.com
• Release date: Dec 9, 2021
• ISBN: 9781794725652

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A Goat On a Boat to Float: The Case Diary of Chinami Chiba

Originally written in Japanese by Takafumi Takada

Translated by Ryusui Seiryoin

Cover illustration by Polka D

Cover design by Tanya

This work was first published in Japan in 2002.

Japanese edition copyright © 2002 Takafumi Takada/ Kodansha

English edition copyright © 2021 Takafumi Takada / The BBB: Breakthrough Bandwagon Books

All rights reserved.

ISBN: 9781794725652

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When summer vacation ended and the latter curriculum of a cram school started, our carefree days as students preparing for university entrance examinations had gone by, and we were beginning to feel the unspoken tension.

The date of the examination (held from January to March in Japan every year) was approaching. But from the point of view based on logic, if a proposition is correct, its contraposition has to be always correct, too. When a supposition (if it is A, then it is B) is true, its contraposition (if it is not B, then it is not A) is also true. When this proposition If the date of the examination is approaching, I will study hard. is correct, then its contraposition also has to be true.

Therefore, I can say that, If I don’t study hard, the date of the examination won’t be approaching.

This logic must not fail, right?

Is there anything wrong with that? No, there must be no fault in my logic, without any doubt.

While thinking about that sort of thing, I was going out with my younger sister. It was on Sunday in September, and the whole world seemed to be filled with refreshing autumnal air.

We were going to visit a famous Buddhist temple named Shibamata Taishakuten, located in Shibamata, Katsushika-Ward, Tokyo. Of course, Chinami-kun would be with us. And for some reason, Shinnosuke would accompany us, too.

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I would like to explain to you about them.

First, about Chinami-kun. His full name is Chinami Chiba.

You may think his name sounds a little strange. I won’t say so because someone might say the same thing about my name, too.

Chinami-kun is the only son of Aunt Tsuruko, who is a sister of my father’s. The Chiba family, which Aunt Tsuruko has married into, is a large landowner in Tokorozawa. They have a golf course in their yard as well as mountains, valleys, forests, and lakes. Considering that Chinami-kun is the only son of the super-rich family, you might think that he is a strange boy or a spoiled brat. But, that completely differs from the truth. He has been a model student since our junior high school days. He even acted as a class representative, for example.

With regard to the appearances, Chinami-kun’s is exactly opposite of mine. I sometimes feel like suing God for the product liability of genetics. Chinami-kun is tall and has beautiful straight hair. I would not have forgiven him for his being what he was if he were an unknown guy. But, I accept him as my friend because he is Chinami-kun. Basically, he is a very good boy.

Chinami-kun’s hobby is to play the flute or the acoustic guitar. He is very good at playing them. I recommend that you listen to his performance one day, if you get a chance. When he was quietly playing the flute in front of my sister and me alone, my heart and soul were so moved and shaken that I wanted to confess my having lived such a miserable life for no reason in particular.

Then, about Shinnosuke, the other guy. His full name, Shinnosuke Aiba, sounds very old-fashioned. He has been my classmate since high school and is going to the same cram school in Yoyogi as I do to prepare