Osamu Dazai was born Tsushima Shuji in Aomori Prefecture.
His father, Genemon, was a landlord. Osamu was born as the sixth son of the Tsushima family. Due to his mother being ill and his father busy working after his birth, he was raised by a nanny for a year before his aunt, Kie, took over until he entered elementary school. Due to their family name, the Tsushima children got good grades irrespective of their actual abilities but Osamu was reportedly a good student and earned his good grades.

On March 4, 1923, Osamu's father died of lung cancer. In April of that same year, he entered Aomori Junior High and left his parent's home to live in a boarding house. His grades remained excellent throughout Junior High and he graduated as the 4th highest graded student out of the school's 148 students. He reportedly read a lot of Akutagawa Ryunosuke, Kikuchi Hiroshi, Shiga Naoya and more well known authors of the time. At 17, he wrote a piece for the "Alumni Association Magazine" and published 12 issues of a magazine called "Mirage" with his friends. It was around the time that he wanted to become a novelist.

In 1927, Osamu entered Hirosaki High School. As Hirosaki at the time had a dormitory system, he would later move in their instead of going to school from his parent's home. He was reportedly shocked at learning that one of his favorite author's, Akutagawa Ryunosuke, had committed suicide.

In 1928, his initial attempt at serialized literature was ended after only one part was published, reportedly due to opposition from his family. He reportedly attempted suicide for the first time in December of 1929. It's believed that, after hearing of the arrests of left wing students (Community Party members) from Hirotaka, he was attempting to kill himself to avoid being arrested.

In 1930, after graduating from Hirotaka, he entered the Department of French Literature at Tokyo Imperial University. Though there was reportedly a test in French to enter aforementioned department, Osamu was admitted under special consideration. However, he reportedly couldn't keep up with the lectures and considered transferring out.

After Osamu told his family that he wanted to marry a geisha, Oyama Hatsuyo, the Tsushima family strongly opposed the union. His brother, Bunji, allowed him the marriage if he would take an allowance of 120 yen (over 200K yen in today's money) and keep her off the family register. He was formally disowned from the Tsushima family. He would later attempt double suicide with bar hostess Tanabe Shimeko in November by drowning in the sea but only Shimeko died as a result. He was accused of assisting her suicide but his family reportedly worked and managed to get the prosecution suspended. The term "No Longer Human (Ningen Shikkaku)" was first associated with him in the newspapers as a result of this situation. He would go on to marry his geisha fiance, Hatsuyo, while recovering from the suicide attempt. The two moved to Tokyo and began their newlywed life their.

In 1932, he wrote "Omoide" and "Gyofukuki" and renewed his determination to be a novelist. With the help of Bunji, he left the Community Party behind in his effort to settle down. His allowance was also dropped from 120 yen to 90 yen.

In 1933, he began publishing work under the pseudonym Osamu Dazai. He published "Gyofukuki" under Osamu Dazai and even launched "Romanesque" which was suspended after it caused a dispute with other writers.

In 1935, he announced the publishing of "Gyakko". He was worried about graduating when in his fifth year of university and, believing his allowance would be cut off, attempted to join Miyako (now Tokyo) Shimbun but ultimately failed. He would go on to attempt suicide again in Kamakura on March 18th. In April, he had surgery for peritonitis and was injected with the painkiller, Pavinal, an oxycodone, during his stay and would become addicted to it. He was removed from university on September 30 due to unpaid tuition.

"Gyakko" would go on to become a candidate for receiving the first Akutagawa Award but was ultimately defeated. His dependence on pavinal would grow increasingly more severe with a reported 50 injections a day. He was also forced into hospitilization by his brother, Bunji.

In 1937, his friend and painter Zenshiro Kodate, attempted to his affair with Osamnu's wife Hatsuyo. Osamu and his wife would attempt to commit suicide in March of that year at an onsen but neither died and subsequently divorced in June of that same year.

In 1938, Osamu met Ishihara Michiko. The two would be married in January 1939. He moved with his new wife to Kofu City. In a mentally stable place, he released several excellent short stories including "Joseito (Schoolgirl)" which was heavily acclaimed. Osamu's first child, Sonoko, was born in 1941. In 1944, his son Masaki, was born.

During the period of World War 2, due to being in poor health with an official diagnosis of tuberculosis, he remained in Japan. He would be evacuated from Tokyo to Kofu due to air raids. With his wife's family in Kofu, he also witnessed the Kofu air raids that say the Ishihara family's home burning down.

After the war, Osamu would go on to publish "Shayo", based off of the diary of an admirer named Ota Shizuko. A serialized work "Pandora no Hako (Pandora's Box)" would also have to be rewritten after the original manuscript was lost due to the fire. In 1947, Ota would give birth to Haruko.

Osamu would go on to become an alcoholic after being a heavy drinker. While his health was deteriorating, he would go on to meet Yamazaki Tomie, a beautician and war widow who lost her husband after just ten days of marriage. Osamu abandoned his wife and children and moved in with Tomie.

In 1948, Osamu wrote "Ningen Shikkaku (No Longer Human)" and "Oto". A friend, Nohara Kazuo, reportedly witnessed Osamu coughing up blood. After threatening to acquire cyanida, Osamu would go on to visit Uji Hospital in Omiya.

Though his friends had attempted to convince him to rest in Tenkajaya where he wrote his work "Fugaku Hyakkei (100 Views of Mount Fuji)", he would go on to commit suicide with mistress Tomie. The two reportedly drowned themselves in Tamagawa on June 13, 1948 but their bodies would only be discovered six days later on what would have been Osamu's 39th birthday. Due to his death, his humor novel "Goodbye" remained unfinished.

On May 23, 1998, the suicide note he sent to Michiko would be published saying "I loved you more than anyone" and that he didn't enjoy writing novels anymore. His suicide note was reportedly written on the draft of a manuscript. Since atleast 1962, he has been portrayed by several actors in movies and in tv dramas. Edit Biography