Rin is a short and thin girl with a light complexion. Her petite stature is due to her having an eating disorder when she was younger and didn't eat enough to be able to get the sufficient nutrients to grow properly. Along with that, she has dark blue hair which is put up into two twin-tails while the rest of her hair is left down and reaches after her shoulders. She also has dark brown eyes to complement her features along with evenly-cut bangs covering her forehead and framing her face. After the shooting incident, Rin now has two bullet scars on both her shoulder and torso.

She often made her appearance while wearing her school uniform which consists of a white blouse and a black long sleeved jacket worn on top along with a striped bow, a light blue skirt, and brown loafers.

In the future, Rin had started to grow out her hair like her brother during the times when he had long hair. Furthermore as an adult, she is always seen wearing formal-looking clothes due to her job of being a lawyer. In addition, she also wears the ring that she made into a necklace which Hanma gave her during their teenage years. She also wears custom made earings that look similar to that of Hanma's except it is made out of rhinestones.

Rin displays a friendly and easygoing demeanor, often having a relaxed perception to her character. In the face of her outwardly calm and tranquil disposition, she harbours utmost hate and anger towards her mother for absuing her and her brother in the past.

Rin is also a kind-hearted and gentle girl as seen when engaging even with someone like Hanma. She isn't someone who discriminates gang members with normal people and instead treats them with equality. This is probably due to the fact of being someone who has strong principles, such as thinking one should not be looked upon differently based on their way of life.

Aside from the previous fact, Rin can sometimes be brash and blunt towards others as a way of protecting herself from getting hurt, due to fact she was once hurt by her mother; someone close who she once considered as family. After that history with her mother, Rin had developed a habit of being on guard with almost every person who she wasn't acquainted with before, in fear of getting hurt again once she had gotten close to them and became someone who she trusts. Rin is also not one to share about herself on her own initiative without having someone asking her about herself.

• "I am aware Shuji isn't a good person entirely, yet to me he's still someone special. He saved me many times when i needed it, that's why I say to me he is kind enough."
• (to Hanma) "So, it doesn't matter if you're in a gang, I would still want to stay with you by your side."

• The name Rin means "dignified, severe, cold" (凛) (rin).
• Rin's surname Tokisaki means "time, hour" (時) (toki) and "promontory, cape" (崎) (saki).
  

• Rin used to be appart of the volleyball club back in middle school but quit later on due to unknown reasons.
• Rin owns a cat but surprisingly enough her cat hates Hanma.
• Rin used to have an eating disorder and was underweight but got better in the future.
• In her free time, she likes doing origami and ends up giving most of them to her friends or even Hanma.
• She likes going to a nearby café almost everyday with her friends after school to hangout.
• She dislikes her brother's handwriting and people who look down on her just because she's a 'weak girl'.
• Her special skill is preparing remarkable dishes.
• Her dream is to become a lawyer in the future and bringing justice to those who need it.
• Her favorite spot is the Rainbow Bridge at Minato City which she once visited with Hanma on one of their dates.