- "My whole life I've been, let's just say, less than popular. But at least I had a few friends. And then Cobra Kai comes to town, and next thing I know, my friends are taking karate and becoming alpha jerks. I'm literally being threatened by my best friend. I just wanted to show I could fight back."
- ―Demetri to Daniel LaRusso[src]
Demetri is a supporting character in season 1 and a somewhat of a main character in season 2 of the YouTube Web Series Cobra Kai. He is the friend of Miguel Diaz, and former friend of Hawk. He is intelligent and sarcastic, but has somewhat low self-esteem. He ends up joining Miyagi-Do Karate in the second season, becoming the third student of the new generation of Miyagi-Do Karate.
Demetri was born sometime in 2002. He befriend Eli Moskowitz at some point prior to Cobra Kai. Demetri was often a subject to bullying.
Demetri is friends with Eli Moskowitz. He soon meets and becomes friends with Miguel Diaz as well, despite warning Miguel about his lowly social status. He is regularly bullied by Kyler, but doesn't feel there is anything he can do about it. After Miguel beats up Kyler and his group Demetri decides to join the Cobra Kai Dojo but soon quits after he is embarrassed by Johnny Lawrence. In the episode Different but Same, he is shown to have a crush on Yasmine. After Miguel wins the All Valley Karate Tournament, he tells Miguel he might join Cobra Kai again.
Despite having limited screen-time in season 1, Demetri's role increases significantly in season 2 due to his character development, as well as story-line. He can be seen as one of the more important characters this season .
Demetri celebrates Cobra Kai's victory at the All Valley tournament with Miguel, Aisha, Hawk and other Cobra Kai members. He soon decides to join again. When he goes back to the dojo to re enroll he sees Johnny's sensei John Kreese, though he does not know who he is. He is happy to see him instead of Johnny as his last encounter with him ended badly. He first tells Kreese his conditions and expectations, but after looking at his tattoos he tells him how anatomically incorrect they are and even touches them. However, an annoyed and angry Kreese hits him. Demetri complains to Hawk about what Kreese did, but Hawk shows no sympathy for him and tells him to man up.
Demetri enough with the bullying joins Miyagi-Do Karate and writes a negative review of Cobra Kai which angers Hawk. He however, struggles at first and does not look interested. When sensei Daniel LaRusso asks him why he is here, he talks about how he has been bullied and now he lost his best friend because of Cobra Kai, and now wants to prove he can fight back. Daniel tries to give him encouragement but Demetri is not confident.
While Demetri along with Miyagi-Do students Robby and Samantha LaRusso (Daniel's daughter) are eating in the mall he goes to the comic book store. While there Hawk and other Cobra Kai members surround him and force him to take down his review of Cobra Kai, but when Demetri refuses Hawk attacks him. Demetri runs away but is soon cornered by them. However, Robby and Sam defend him and beat up the Cobra Kai's.
When some of the Cobra Kai's who bullied him in the mall join Miyagi-Do Demetri, Robby and Sam are unhappy but Daniel lets them join. After Demetri gets into an argument with one of the former bullies (Chris) Daniel decides to tell them the time he joined Cobra Kai in order to show how everyone Cobra Kai can corrupt people and people can change. Demetri then starts to get along with Chris.
Overtime Demetri is able to use his intelligence to defend himself while training, which makes him before confident. During a party at Moon's house Demetri attempts to bond with Hawk by talking to him about "Doctor Who'. His attempt seems to work as Hawk is interested. However, after he suggests to Hawk to have inner peace Hawk dumps beer on his head. Fed up with his treatment, Demetri gets revenge by taking a mic and announcing to everyone all the embarrassing stories about Hawk. An angry Hawk tries to attack him, but Robby and Chris stop him and the cops arrive. Hawk threatens Demetri that he will beat him up at school.
When a school brawl between Cobra Kai and Miyagi-Do occurs the next day at school Demetri gets a teacher and asks him to stop the fight but he refuses. When Hawk spots Demetri Demetri runs away and Hawk chases him. Demetri tries to hide in the computer lab but Hawk finds him. Demetri runs away again. However, Hawk eventually catches him and starts attacking him. After being hit twice, Demetri uses Miyagi-Do Karate to block and counter all of Hawk's attacks. He then kicks Hawk into a trophy case. However, he apologizes to him after, showing he still cares for Hawk despite his bullying.
Demetri is a sarcastic and awkward guy with low self-esteem. He considers himself a jaded realist but he actually has no confidence in himself. When Johnny embarrasses him on his first day at the Cobra Kai Dojo Demetri immediately quits.
Demetri isn't an important character in season 1. His screen-time is limited and he doesn't have any sort of story-line. Outside his self esteem issues and friendship with Miguel and Eli, nothing is known of him.
- "Demetri, you are the most neurotic person that I know. You always expect the worst."
- ―Daniel LaRusso to Demetri[src]
Unlike season 1, Demetri becomes a more developed character with a story-line. His sarcasm is still present, but has reduced significantly. At first he attempts to re enroll in Cobra Kai, but after Kreese hits him he writes a negative review about Cobra Kai, which results in his best friend Hawk ending their friendship and bullying him. He eventually joins Miyagi-Do Karate. Despite struggling and still showing lack of confidence, as time goes by he is able to learn the Miyagi-Do Karate technique, which allows him to become more confident and a better fighter. After Hawk pours beer on his head Demetri gets revenge by telling everyone embarrassing stories about him (namely, Hawk's bawling when Dobby dies, while Demetri and Him watch Harry Potter, and especially Hawk having sleep enuresis, to the point of Demetri's mom tackling this, by having a seperate air-mattress for Hawk, during sleepovers, that she [Demetri's mom] calls "Eli's waterbed"). During the school brawl Hawk chases Demetri who tries to get away from him, but Hawk eventually catches up to him and starts attacking him. Demetri however uses his Miyagi-Do Karate technique to defend himself. He then kicks Hawk into a trophy case, injuring him as a result though he does apologize, showing that he still cares about him despite the latter's constant bullying.
Demetri is not a natural fighter. He is never seen fighting until he joins Miyagi-Do, and even there he struggles with technique. However, he does benefit from his sharp intellect, instantly deducing that Daniel's painting and sanding chores are muscle memory exercises. Daniel eventually makes use of Demetri's intelligence, presenting a blocking drill as a puzzle to be solved. This helps Demetri become a fairly solid defender, making him the opposite of the aggressive Hawk. During his fight with Hawk he successfully uses the Miyagi-Do technique to counter all of his former friend's strikes, finally defeating him by kicking him into a trophy case.
Demetri's victory over Hawk can indicate that despite not being physically strong, his technique helps him triumph over opponents that are physically stronger but lacking technique.
Demetri's lack of strength is compensated by his speed; according to Daniel, he can run the 100-yard dash in under ten seconds, which is over 20.45 miles per hour (meaning he can run a mile in under two minutes and 56 seconds).
- Demetri can be compared the following characters
- Daniel LaRusso - Similarly to how Daniel ran from the Cobra Kais during the Halloween party, he ran from the Cobra Kais in the mall. Unlike Daniel, who brought that attack on himself by soaking Johnny with a hose, Demetri had been minding his own business when threatened by Hawk, and ran out of a sense of self-preservation.
- Demetri is a supporting character in season 1 with no story-line, but season 2 sees his character being developed and having a story-line, making him somewhat of a main character that season.
- In Season 1 Demetri is weird, sarcastic, awkward and even desperate. In Season 2 however, he is shown in a more serious and sympathetic light.
- Demetri's sarcasm in season 2 is much less than it was in season 1 most likely becuase he had a story-line in season 2.