- "A hero is someone who will risk everything to protect what he loves!!"
- — Rena —
In Legend of the Twilight, Rena appears as a chibi version of the character BlackRose. Like the legendary .hacker she has pink hair and wears a rather revealing set of pink armor, much to the shock of her brother.
In her offline appearance, Rena has a long dark brown hair in a full fringe much like his twin brother Shugo and wears casual clothing. When she was in a comatose state, she was seen wearing a patient uniform and has a dextrose on her left arm.
Rena is fiercely protective of her brother Shugo, and makes no effort of hiding this. She doesn't like being ignored by him, or seeing him act "unheroish", and has many ways of getting him to do what she wants, her favorite method being a quick smack upside the head. Despite their slapstick relationship, Rena and Shugo are extremely close, and she will support him in almost any situation.
Rena lives with her parents and her twin brother Shugo somewhere in Japan. She is in her third year of junior high, which she attends with her brother. Komiyama is also in her class. She apparently used to be rather forgetful, and would get lost on a regular basis, forcing Shugo to go look for her. Her birthday is December 12th, her blood type is O, and her height is 163cm. Her weight is 45kg. Her hair is brown in color.
Rena enjoys playing The World and hanging out with her brother. Her other hobbies are listening to music and chatting with friends. She was a member of the softball tennis club until her third year.
The Legend of the Twilight anime begins when Rena wins a special contest giving her an avatar modeled after the legendary .hacker BlackRose, and, entering her brother Shugo too, won an avatar modeled after Kite. Since their parents are divorced and each sibling lives with a different parent, Rena uses The World as a way to hang out with and have fun with her brother.
Rena, already familiar with the game, tries to teach Shugo how to play, but in their first adventure they are attacked by a powerful Data Bug sent by a group of hackers to destroy their special characters. Shugo is killed by the monster but rescued by Aura, who gives him a Twilight Bracelet. Meanwhile Rena tries to flee from the creature, cornered at the top of a tower she is rescued by Balmung who holds off the monster until Shugo reappears and defeats it with Data Drain. She later falls into a coma when killed by a data bug and is held on a mirror server, in a sleep like state until awakened by Aura.
Like in the anime, she wins the Avatars and uses them as a way for them to spend time with each other. However, they live together with their parents who are not divorced in the manga. At first Shugo is shocked that her avatar wears a revealing set of armor but eventually gets used to it. Later on they meet the treasure-seeking wavemaster Mireille, Ouka a powerful werewolf, and the friendly but naive Hotaru. On their adventure she helps Shugo find Aura and she feels slightly jealous of Zefie getting all her brother's attention and ends up being called "kogal" or "ganguro" by Zefie. (Ganguro is a trendy Japanese teen that is tanned with white makeup. This appears to greatly offend Rena)
A bonus e-mail reveals that Hokuto and Rena still exchange e-mails, and one from Hokuto mentions Rena is currently picking out a college to go to.
An AI of Rena appears with a counterpart of her brother Shugo, reminiscing about their old adventures on a short adventure to help a lost Aina, completely unaware of their virtual nature before vanishing once again.
- A Rena wallpaper is unlockable in .hack//Outbreak and Rena (LINK)profiles herself during the Tanabata event; say that she is a Gemini, her favorite color is red and that she enjoys chatting online with her friends and listening to music.
- Rena's name is mistranslated as "Lena" in the English version of Rebirth. It is also mistranslated as Reina in the plot summary of volume 2 of the TokyoPop manga.
- In the anime, when Rena disappears, Shugo tries calling her. A scene is shown at her house with the phone ringing. The ring tone is "Obsession" by See-Saw, which is the opening to .hack//SIGN
- In the manga, Rena is afraid of ghosts. It is first revealed when she, Shugo, Mistral and Ouka enter a haunted house within The World as part of a special event in Login 7.
- Ironically, during the Twilight Incident, she lived in the same apartment complex, and most likely knew, the original BlackRose (And Kazu as well) in real life, though is still unaware of her identity as the famous .hacker.
- In the manga Rena has a crush on Balmung (which is ironic since the original Blackrose hated Balmung in the games)
- Rena has a small appearance in the movie Kick-Ass at atomic comics.
- At the start of the ending sequence of the anime, she and her twin brother Shugo appear in their offline appearances but their faces are not shown.