Her goal in life is to make the entire world smile. Her family is super rich and lives in one of the biggest houses around the area.
Kokoro has large, rounded yellow eyes and long, straight, waist-length platinum blonde hair. Her fringe is cut unevenly and separated into two parts. She has thin forelocks that touch her shoulders.
Her casual attire consists of a red and white striped t-shirt with fluttery sleeves, blue denim short overalls, and a hair tie with red ribbons on her wrist. During winter she wears a red sweater with a pixelated snowman and snowflakes on it and knitted shorts and a beanie with fluffy balls dangling from it. During summer she wears a white and blue T-shirt, a red ribbon-belt, denim shorts, and a necklace.
An idealistic and charismatic young girl coming from a ridiculously rich family, Kokoro dreams of making the entire world smile from music. She effortlessly attracts others to her due to her bright and bubbly nature and often manages to get them swept up into her easygoing pace. Because of her charismatic and naturally imposing personality, she is often able to do and get what she wants. She is also extremely curious and easily amazed, charmed by new things she discovers in the world around her.
Although Kokoro has the optimism and charm of a natural leader, she is also quite scatterbrained and ditzy, and would not be able to get much done without the others in the group helping her. She also has said that she doesn't know what it feels like to be sad, didn't know what stress was until Marina told her and always does her best to combat any kind of negative feelings. Adding to her status a rich girl, she is ignorant about certain normal things.
A list of characters Kokoro interacts with in the game (during Lives and in the dialogues at the end of every game).
Tsurumaki (弦巻): Tsuru (弦) means "bowstring" and Maki (巻) means "scroll, book".
Kokoro (こころ), from the kanji "心", means "heart".
- She refers to everyone (including Marina) with their first names and without using honorifics, similar to Chiyu.
- She has the same height as Yukina, Rokka, and Himari.
- Kokoro thinks reading, especially reading picture books is fun and often loans them from the library.
- Like Hina, Kokoro is the only member of her school's Astronomy Club. In fact, she mentions that until recently, Hanasakigawa did not have an astronomy club, although from this story it is implied that a faculty member created the Astronomy Club as an excuse to avoid punishing her for being on school grounds late at night (and facing repercussions from the powerful Tsurumaki family).
- Kokoro mentions in one of her summer dialogues that her family owns a private beach, and in another one of her autumn dialogues, that they own a mountain. They also own a vacation home at a southern island called "Happy Happy Island".
- The suits have given Kokoro a train pass that is unique in that, instead of a remaining balance on the card, it only shows "Tsurumaki".
- Kokoro is so hyper and acrobatic that usually only the suits - her three bodyguards - can manage to stop her. Her body is very nimble and such she is able to do backflips even while wearing a furisode.
- Some fan theories say that Kokoro is a genius but she doesn't realize it.
- Kokoro started loving zombies after reading the spin-off manga and seeing the movies for Rimi's favorite horror series.
- In the Ojamajo Doremi collaboration, her design was based on Asuka Momoko.
- In Senki Zesshou Symphogear XD Unlimited's collaboration with BanG Dream! Girls Band Party!, her 2nd stage outfit was used as the design for Akatsuki Kirika's card.
- Shining Through the Rain/Card Story#Special Episode
- Searching For Stars/Event Story
- Happy Adventure! ~Treasure Island Smiles~/Event Story
- I'm a Penguin Too!/Card Story
- New Years! Omikuji Madness/Event Story
- File:Loading Screen Comic 040.jpg
- Beatin' In The Rain/Event Story
- Fruits of Our Labor/Card Story
- Band Girls Of The Dead/Event Story