1. Thirteen is born on February 3, she is currently 29 years old in the series, she’s 180cm tall, and she was born in the Kagoshima Prefecture.
Although her gender identity has been debated during MHA’s run, it’s been determined that in the localisation and the first four School Briefs light novels Thirteen was initially referred to with “he/him” pronouns.
However, in the anime, this was later changed so that Thirteen would use “she/her” pronouns. In the second databook, Thirteen is again confirmed to use “she/her” pronouns and all content henceforth has remained consistent with the use of “she/her” pronouns.
2. Thirteen is said to like museums and self-learning documentaries. She’s also a very passionate person, wanting to save people and encourage students to use their Quirks for good as heroes.
Her passion has led her to develop her own training facility (the Unforeseen Simulation Joint) to train students in search and rescue. She’s also very passionate about Quirks used for creation and assistance rather than destructive and battle-focused quirks.
She’s also shown to be very polite, “wise,” and not hesitating to join in combat against villains to protect others despite not being a ‘combat pro-hero.’ This is reflected in her stats according to the Ultra Archive Analysis:
Power 4/5 (B)
Speed 2/5 (D)
Technique 4/5 (B)
Intelligence (4/5) B
Cooperativeness (5/5) A
And also the Ultra Analysis:
Power 4/6 (B)
Speed 2/6 (D)
Technique 4/6 (B)
Wits 4/6 (B)
Pulling Force (5/6)
3. Thirteen’s surname “Kurose” contains the kanji for “black” (黒 kuro) and “rapids, current” (瀬 se), and her first name Anan contains a particle used to mean “sub-” (亜 a) and “south” (南 nan).
The official MHA Twitter page also showed Thirteen’s prototype design, revealing that her prototype’s hero name was No. 6 and her real name would have been “Hirooki Anakuro” (written as 穴黒央宙 in Japanese). This means her real name would have literally meant “Middle Space.”
It’s also believed that her hero name and the astronaut-like costume are references to NASA’s Apollo 13.
4. Her sketch in Volume 33 shows that her forearms are black, likely an effect of her Quirk. This is suggested to be because when she was hit by debris during the war while helping other heroes escape, her hands became heavily injured.
5. Thirteen and a Class 1-B student called Kosei Tsuburaba (the guy from the sports festival on Mononoma’s team who can create solid air) are the only MHA characters in the main series so far that have received more than one volume character profile.