At an early age, however, he was adopted by his uncle Takano Gensai who had studied medicine under Sugita Genpaku and influenced Chōei to follow in the same profession. He first studied medicine in Edo in 1820 after winning money in a lottery that he used to pay his way. There he first studied under Sugita Hakugen, then Yoshida Chōshuku, who gave him the name Chōei.
After the death of his teacher in 1824 he took over some of the teaching duties in the school.
A year later he left for Nagasaki to study under Philipp Franz von Siebold. There he paid for his education by writing papers about Japanese life for von Siebold, gathering plants and translating books from Dutch to Japanese. After the school was shut down and von Siebold expelled from Japan in 1828 Chōei was forced to flee.
He finally settled in Edo in 1830 where he wrote his Fundamentals of Western Medicine. There he met Watanabe Kazan, a government official sharing an interest in Western learning. They both attended meetings of Shōshikai, a study group of intellectuals interested in foreign affairs.
In 1838 Chōei married and then published The Tale of a Dream, a book critical of the Tokugawa shogunate's handling of the Morrison Incident (1837). Since he was of samurai status he was dealt with rather harshly and sent to the Kodenmachō prison in Edo where he spent five years of his life sentence in the commoners' section. In 1844 he arranged to have a fire started in the prison and made his escape.
He then spent the rest of his life in hiding using various aliases. At one point he is said to have poured acid on his face to disguise his appearance and elude arrest. He was finally caught by the police in 1850.
Rather than return to prison or face execution Chōei resisted. He killed three police with his bare hands before he was either beaten to death or stabbed himself in the neck. It is not clear exactly how he died.