Kodaira suffered from
stuttering during his childhood. He joined the Imperial
Japanese Navy in 1923. He paticipated in the Jinan
Incident. He killed six Chinese soldiers in 1928. He
raped or murdered many Chinese women in China. In Taku
Forts, he stuck a sword into the belly of an expectant
mother. The exact number of his victims in China is
unknown.
He married in 1932 after he returned
to Japan. His wife ran away from him because he had a
child by another woman. He became angry, and attacked
the house of his wife, killing his father-in-law and
injuring six others with an iron rod on July 2, 1932. He
was arrested, and was released in 1940.
It is believed that he raped and
murdered ten women between May 25, 1945 and August 6,
1946 in Tochigi and Tokyo. At the fifth murder, he raped
a dead woman. On August 20, 1946, he was arrested.
He denied three murders in the court,
and the district court admitted seven of ten murders on
June 18, 1947. One of the unproved three victim was
unidentified. The Supreme Court sentenced him to death
on November 16, 1948, and he was executed on October 5,
1949. Before he was executed, he smoked a cigarette and
was calm.