Male

Although he wrote in his own book that he was "5 shaku 6 sun 3 bu (approx. 169 cm)," his actual height was about 173 cm to 175 cm.

Chiseled facial features
A melancholy atmosphere
In his own essay "Appearance," he wrote that he had a "large face," among other things.

He has self-destructive and reckless tendencies, is sloppy in his relationships with women and finances, and repeatedly attempts suicide.
He has a charm that draws people in with his affability and approachability, and was adored by many friends and disciples.
He is extremely eager to please, a witty and humorous talker. At drinking parties, he would fire off jokes one after another and make those around him roar with laughter with his comical gestures. To avoid making others feel awkward, he often deliberately spoke in a playful manner.
In Dazai's novels, such as "No Longer Human" and "The Setting Sun," there are many passages written in a style that directly addresses the reader. This is because he loved rakugo (traditional Japanese comic storytelling) and valued the rhythm of speech.

In reality, Osamu Dazai basically used "boku" (I) in letters to friends, diaries, and essays describing his daily life. He would use the polite "watashi" (I) when addressing older writers (such as Masuji Ibuse) or people he needed to be formal with.

Osamu Dazai was tone-deaf, a fact he himself acknowledged. Once, an acquaintance pointed this out quite harshly, saying, "Your singing has absolutely no rhythm, Sensei. It's like a lion roaring in the jungle." Far from getting angry, Dazai readily admitted it, saying, "Ah, so you've seen through me. To be honest, I am tone-deaf," a rather endearing anecdote.

He loved hairy crabs (kani), a specialty of his hometown, Aomori. In his novel "Tsugaru," there is a scene where he drinks until late at night in front of a mountain of crabs. He was very fond of the seasoning "Ajinomoto" and would sprinkle it generously on everything (sometimes turning his miso soup completely white). He loved rakugo, movies, and Western clothing, and these influenced the tempo of his own conversation. He was also particular about fashion from a young age and enjoyed posing for photographs.

Dogs (intensely disliked): He was a die-hard dog-hater who was "simply terrified of dogs." Cold water (baths and washing face): He was very sensitive to the cold and disliked washing his face with cold water or taking cold baths. (It is famous that the writer Yukio Mishima once sarcastically told him, "Your problems would be solved by rubbing yourself down with cold water and doing some exercises.")