Main title 「悪逆女王」(AKUGYAKU-JOHOH) means ‘CRUEL EVIL QUEEN’.
紫炎（Shien）is daughter of Yakuza Oyabun.
She has TATOO of 不動明王(FUDOH-MYOHOH) in her back.
不動明王 is God of Justice who arms with Rope in his left hand and Sword in his right hand.
紫炎 fight enemy in the situation ‘on the job killing’.
She has plenty experience of killing but she is only 16 years old .
Sub-titles are based on Buddhism concept. For example, episode 19th 「近づく所は墓場なり」means ‘Life is very short, you are almost in graveyard already’.
紫炎 is considering: ‘Why can I still have TATOO of 不動明王 ? I’m just evil person that have killed more than a hundred people.’
At the same time she goes to high-school to get license of lawyer.
Of course, she will use the license for YAKUZA business in the future.
If you are interested in this novel, you can read with google translation.
https://kakuyomu.jp/works/1177354054898259877