- He, along with several other characters, made an appearance in the mobile game Love Heaven as a limited time character.
- His constant attempts to commit suicide with a beautiful woman could be an allusion to his real life counterpart's attempted double suicide with Shimeko Tanabe and Hatsuyo Oyama. His attempt with his lover Tomie Yamazaki was ultimately successful.
- It's also possible that his suicide attempts serve as a reference to No Longer Human's protagonist Ōba Yōzō's multiple suicide attempts throughout the story, which is considered to be a reflection of Osamu Dazai's turbulent life.
- He was the youngest executive in mafia history.
- In real life, he is often grouped together along with Sakaguchi Ango and Oda Sakunosuke as the Buraiha or Decadent School. And on the series, this is often alluded, because the three used to meet in a certain bar, as seen in Dazai and the Dark Era, and illustrated on the calendar.
- He is nicknamed as 'Bandage-wasting Device' by Kunikida at Chapter 2 / Episode 2. Though, Dazai somewhat hurt while Kunikida called him as, "Bandage Wasting-device". Blame him because he is always trying to commit suicide, then injured and got much bandage covered almost his whole body.
- Dazai usually refer himself by gender neutral phrase "watashi" rather than the more masculine phrases like "boku" or "ore".
- It seemed he was prefer with cats than dogs.
- Dazai can't takes spicy foods.
- Dazai's girl type was all type, but the least prefer whose glasses girls. He even said he wanted to take the glasses off of many beauties who wore them. In reality, Dazai was quite shy. Glasses gave him the impression that he was 'being watched', or that the wearer was looking right down into his soul, which was a very uncomfortable feeling for him.
- Dazai was much better with 'being heard' than 'being seen'. He was a very talented speaker, and many of his works were written through verbal dictation.
- Dazai was popular with ladies, but Dazai almost made ladies whom attracted by him, mostly crying. It stated by Chuuya in chapter 31.
- Dazai has very high tolerant with alcohol.
- Dazai could only eat a can of crabmeat in as his meal for a day.
- Since Dazai hates dogs, whenever he saw that animal, he will making fun with them or instead, he will just run. But, he is okay if with cats.
- He always kept a match that was belonged with Odasaku, as only treasure from his best friend who already deceased; because in past, Odasaku was a smoker.
- His black coat while he still in Mafia, was a coat had given from Mori Ougai. But he then burnt it after left Port Mafia.
- Based on Light Novel: Dazai Osamu Entrace Exam, Dazai can't driving.
- Dazai can cook a simple dish like Chazuke (BSD Drama CD - Onsen) but mostly his cooking is somewhat odd, like a hard-boiled tofu (LN: Dazai Osamu and The Dark Era) which that tofu was hard like rocks, also spirited chicken hotpot, and maybe superhuman strength hotpot.