Height: 168 cm
Weight: 48 kg
Age: 16
Birth date: February 20
Blood type: B
Nationality: Chinese

Komui's younger sister, and assistant Head Officer. Her parents were killed by an Akuma when she was very young. Because she is an Accommodator, the Black Order took her away from her only remaining family member (Komui) to Headquarters against her will. For three years she was never allowed to leave the place, which felt like a prison to her. Because she attempted suicide, she had to be restrained and tied to her bed. However, once Komui joined the Black Order, Lenalee became more at ease in the Black Order. She once told Allen that her "world" consists of her friends and family; if something terrible ever happened to them, she would be devastated.

She is an Exorcist whose anti-Akuma weapon is a pair of boots, "Dark Boots." That, when invoked increases one's speed and strength greatly in the legs.

Aside from being able to have great speed, she can also fly with her boots. Techiniques shown so far:
- Onkyou no tougi: Otokase
- Suijou no tougi: Mizukase
- Enbu Kirikaze
- Shittsui no tougi: Tetsukase

After the battle against the Level 3 Akuma, Lenalee lost the ability to use her Dark Boots for period of time. However, it has come to mind that after the battle, her innocence may be the heart of the innocence.

Manga spoilers:
In chapter 153 she made a promise with her innocence so it would become stronger to protect everything she loves, and so it liquified and fused with her blood, creating a better version of her Dark Boots. After defeating the Level 4 Akuma, the boots transformed into a red ring that stays on her legs until the innocence is activated.

She is the first known exorcist to create this new type of innocence named "Crystal Type."
(Source: Wikipedia)