Zen

Zen is the main character of the Thai martial arts film ช็อคโกแลต (Chocolate).

Character creation
The crew did research and brought DVDs for actress Yanin Vismitananda to watch, including Rain Man, Awakenings, Forrest Gump and case studies of autistic people. She combined different aspects from different people to form the character.

Biography
Zen is the daughter of Yakuza boss Masashi, and his Thai lover Zin. Her parents split before her birth, with Zin suggesting Masashi goes back to Japan due to troubles with the Thai gangster No. 8, who was Zin's previous lover.

At a young age, Zen is found to have "problems with brain development." Zin writes to Masashi about her daughter, although these letters are also read by No. 8, who goes to visit Zen and Zin and threaten them.

They move houses and end up living next to a kickboxing school, where Zen becomes obsessed with martial arts. She learns both from watching the kickboxers next door and from watching martial arts films. One day after work, Zin and Zen see a boy (Mangmoom) being bulled, and Zin ends up taking him in.

Years later, Zen's mother is diagnosed with cancer, but they cannot afford the chemotherapy. Moom tries using Zen's uncanny reflexes to earn money by letting people's throw balls at her, which she catches with high precision and speed. This doesn't bring in enough money, but Moom soon discovers a book that notes all the people who owe Zin money from her maffia days. Moom and Zin go visit various people to get their money back, with Zin taking on massive loads of gangsters in hand-to-hand combat.

Zen asks Misashi for help when they are again threatened by No. 8, who has discovered that Zen en Moom have been collecting money that technically also belongs to him. Zin brings Zen with her to confront No. 8 to try achieve a peaceful resolution after he has kidnapped Moom. However, a fight breaks out. Zin takes out many of No. 8's henchman, but ends up against Thomas - a young man who is implied to be No. 8's son and has Tourette's - who initially gains the overhand over Zen, but she ends up taking him out after mimicking his fighting style. Zin is mortally wounded in battle, and Zen takes out the remaining henchman and No. 8 himself. Grieving over her mother's corpse, Masashi ends up adopting Zen.

Autism
The director has stated "I love the idea of an autistic child with a family relationship in what is essentially an action film".

The majority on the film takes place when Zen is a young woman. She doesn't speak a lot, and often uses simple and incomplete sentences. She shows a variety of stims throughout the film, including hopping from foot to foot, rocking in a rocking chair, jumping, hitting her head when she is upset, and flapping her hands. She enjoys swinging. Chocolate candies seem to be a comfort food - her mother gives her a tube of them when she was a little girl, and is seen eating them on multiple occasions. She sorts the candies by colour, and often eats them in very martial artsy ways, such as by bouncing them off another object into her mouth. Another comfort object is a doll that was given to her by her mother to remind her of her father - she often (but not always) has this with her.

She has excellent hearing, which she uses to locate opponents in combat, and hear where projectiles are coming from. The sound of flies, however, is extremely upsetting to her.

She has a ton of martial arts films on DVD, as well as some martial arts video games.