was a Japanese ''

samurai were the hereditary military nobility and officer caste of medieval and early-modern Japan from the late 12th century until their abolition in 1876. They were the well-paid retainers of the '' daimyo'' (the great feudal landholders). They h ...

'' of the late Edo period. Prominent as Navy Minister of the

Republic of Ezo The was a short-lived separatist state established in 1869 on the island of Ezo, now Hokkaido, by a part of the former military of the Tokugawa shogunate at the end of the ''Bakumatsu'' period in Japan. It was the first government to attempt t ...

, he later became famous as the first head of the

Japan Meteorological Agency The , abbreviated JMA, is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. It is charged with gathering and providing results for the public in Japan that are obtained from data based on daily scientific observation an ...

. Also known as or .

Early life

Arai Ikunosuke was born in the Tedai-cho district of Edo, near the

Yushima Seidō , is a Confucian temple () in Yushima, Bunkyō, Tokyo, Japan. It was established in end of the 17th century during the Genroku era of the Edo period. Towards the late Edo period, one of the most important educational institutions of the sh ...

shrine as the son of the Tokugawa ''

gokenin A was initially a vassal of the shogunate of the Kamakura and the Muromachi periods.Iwanami Kōjien, "Gokenin" In exchange for protection and the right to become '' jitō'' (manor's lord), a ''gokenin'' had in times of peace the duty to protect ...

'' Arai Kiyobei. His father donated his money to aid villagers from the flood of Fujigawa, which in turn angered the Tokugawa Shōgun. He began learning the

Chinese classics Chinese classic texts or canonical texts () or simply dianji (典籍) refers to the Chinese texts which originated before the imperial unification by the Qin dynasty in 221 BC, particularly the "Four Books and Five Classics" of the Neo-Confuci ...

at age 7, and on the recommendation of his uncle, starting at age 12 he studied swordsmanship ''( Jikishinkage ryū'' and '' Shingyōtō-ryū),'' archery, and horse riding. At age 14, he entered the Shogunate's academy at '' Shoheizaka,'' and at age 18, he began to study Western-style gunnery. He began his career in the Shogunate at age 20, entering into Dutch studies (''

rangaku ''Rangaku'' (Kyūjitai: /Shinjitai: , literally "Dutch learning", and by extension "Western learning") is a body of knowledge developed by Japan through its contacts with the Dutch enclave of Dejima, which allowed Japan to keep abreast of West ...

),'' and was posted as an instructor at the

Nagasaki Naval Training Center The was a naval training institute, between 1855 when it was established by the government of the Tokugawa shogunate, until 1859, when it was transferred to Tsukiji in Edo. During the Bakumatsu period, the Japanese government faced increasing ...

Life in the 1860s

After studying mathematics, sailing, and navigation, Arai was appointed a director of the Naval Training Center in 1862. However, he was reassigned to the Shogunate's '' Kōbusho'' military academy in 1864, and it was there that he worked with

Ōtori Keisuke was a Japanese military leader and diplomat.Perez, Louis G. (2013)"Ōtori Keisuke"in ''Japan at War: An Encyclopedia,'' p. 304. Biography Early life and education Ōtori Keisuke was born in Akamatsu Village, in the Akō domain of Harima Pro ...

, learning French-style infantry tactics in

Yokohama is the second-largest city in Japan by population and the most populous municipality of Japan. It is the capital city and the most populous city in Kanagawa Prefecture, with a 2020 population of 3.8 million. It lies on Tokyo Bay, south of T ...

in 1865.

Boshin War

In 1868 during the Boshin War of the

Meiji Restoration The , referred to at the time as the , and also known as the Meiji Renovation, Revolution, Regeneration, Reform, or Renewal, was a political event that restored practical imperial rule to Japan in 1868 under Emperor Meiji. Although there were ...

, Arai was assigned as a captain to the Shogunal Navy, and together with Enomoto Takeaki departed

Shinagawa is a special ward in Tokyo, Japan. The Ward refers to itself as Shinagawa City in English. The Ward is home to ten embassies. , the Ward had an estimated population of 380,293 and a population density of 16,510 persons per km2. The total are ...

Harbor when Edo was surrendered to the Imperial Army. Traveling to Hokkaidō, he became Navy Minister of the new

, and while he took part in the

Naval Battle of Miyako Bay The was a naval action on 6 May 1869, in which samurai loyalists of the former Tokugawa shogunate under the flag of the newly formed Republic of Ezo failed to take over the , the flagship of the Imperial forces of the new Meiji government. It wa ...

and the Naval Battle of Hakodate Bay, the Ezo forces were defeated, and Arai was placed in prison, where he remained pending a

sentence of death ''Sentence of Death'' is an EP and the debut release by German thrash metal band Destruction, released on 10 November 1984 by Steamhammer Records. Track listing Personnel ; Destruction * Schmier – bass, vocals * Mike Sifringer – gu ...

. During this time, he wrote the first English-Japanese dictionary.

Meiji Era

With his sentence of death commuted, Arai worked with Enomoto in land reclamation for a time, before working in the Agricultural School, as well as becoming head of a women's school. He was later put in charge of the Central Meteorological Agency during the

Meiji period The is an era of Japanese history that extended from October 23, 1868 to July 30, 1912. The Meiji era was the first half of the Empire of Japan, when the Japanese people moved from being an isolated feudal society at risk of colonization ...

, became the first person to photograph the

corona Corona (from the Latin for 'crown') most commonly refers to: * Stellar corona, the outer atmosphere of the Sun or another star * Corona (beer), a Mexican beer * Corona, informal term for the coronavirus SARS-CoV-2, which causes the COVID-19 di ...

of the sun in Japan, during a solar eclipse in 1887, introduced the meter system, founded Hokkaido University, and established standard time. Later in life, together with his old colleague

, he contributed to the magazine ''Kyū Bakufu'', writing articles about his experiences in the 1860s, as well as about the navy of the former Shogunate. Arai died of

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

in 1909, at the age of 74.

References and further reading

*Fukunaga Kyōsuke. ''Kaishō Arai Ikunosuke''. Tokyo: Morikita Shoten, 1943. *Harada Akira. ''Arai Ikunosuke''. Tokyo: Yoshikawa Kobunkan, 1994. *Hillsborough, Romulus. ''Shinsengumi: The Shogun's Last Samurai Corps''. Tuttle Publishing (2005).

External links

Information on the Shogunate navy, including Arai's command
{{DEFAULTSORT:Arai, Ikunosuke 1836 births 1909 deaths Samurai People from Tokyo People of the Boshin War People of Meiji-period Japan Deaths from diabetes Government ministers of Japan Japan Meteorological Agency