Kelas Internasional

School staffs

• Pak Budi (Tarra Budiman) is the main character of the show. He teaches his students how to speak Indonesian. He is very patient, even throughout all the squabbles and problems in his class. He has asthma and must carry an inhaler. Nowadays, he's rarely to be seen in the class, therefore Bu Rika replace him (or another teacher that she appointed)
• Bu Rika (Maya Wulan) is the principal of the school, being promoted from a teacher. She wears glasses, and likes to play mini golf. She is terrified of chickens. She loves to eat and has tried diets many times. They haven't worked. She used to like Carlos.
• Supri Eben (referred to as Sueb) (Boy Idrus) is the only cleaning service of the school. He calls Bu Rika "Mother" due to her resemblance to his mother. He speaks the Betawi dialect of the Indonesian language but mixes English into it.
• Bu Kantini (Niniek Arum) is the chef and cashier of the school's canteen. She is a staunch collector of debts. She used to like Carlos. She likes jasmine and also she's the former gangster.
• Bu Silvy (Sylvia Genpati) is the Substitute Teacher

All-season students

• Abbas (Abbas Aminu) - He is often out of money and has debts. He is often scolded by Bu Kantini because of them. During Season 2, he tries a number of ways to get money, including selling "Moooooo Milk" and duck eggs on the roadside. In Season 3, he used to sell "cangcimen", or combination of peanut, watermelon seeds, and candy
• Ling Ling (Wiwiek Michiko) - She likes to sell, and she gets in trouble during class for doing so. However, she is the best student in class. Due to her accents, she cannot pronounce the "R" sound. She once competed with Abbas' milk selling with "Mbee Milk". She used to go out with Kotaro until she found out that he was much older than her. In the beginning of season 3, together with Nicole, she bought a café previously owned by Carlos through his wife, Angelina.
• Kotaro (Nobuyuki Suzuki) - He works as a shiatsu masseur until Season 2. In Season 3, his business got bankrupt. Due to his accent, otherwise, he cannot pronounce the "L" sound. He is the second best student in class. He has food allergies.
• Lee Jeong Yu (Lee Jeong Hoon) - He likes K-pop music, and is often nicknamed him as a "failed boy band".

Season 1 students

• Carlos De Vega (Carlos Camelo) He owns a cafe. He graduated at the end of Season 1 after marrying Angelina. But, in Season 2, he sometimes reappeared when he came back to his café.
• Angelina (Loyd Christina) She has prawn allergies. She graduated at the end of Season 1 with Carlos. She used to like Pak Budi, but finally got married with Carlos. She was the most beautiful in the class until she graduated and was replaced by Nicole.
• Tyson (Tyson Lynch) He is an actor. He graduated at the end of Season 1 due to his work schedule. However, he made a brief reappearance in Season 2 during his work break. He likes Angelina, and often fought with Carlos about it, but finally he gave up when he got a new girlfriend.
• Mrs. Palak (Palak Bhansali) She cannot speak Indonesian well, and she often breaks into her native language. She is married and she graduated at the end of Season 1. She has a pet snake named Vijay and a little daughter named Sharmila.

Seasons 2 and 3 students

• Daniel King, or DK (Langston Hues) - When introducing himself, he said that he was from Detroit, MI. He loves Hip Hop. He likes Nicole.
• Han Yoo Ra - She brings a stuffed shark around, whose name is Kosong (Indonesian for "empty" or "zero"). She has fallen in love with Kosong. Kosong is also very useful for blaming whenever she makes mistakes, which she often does. Once Kosong was lost and she was in shock. She also had hallucinations during this time. She has been named the cutest in class. She is rather careless.
• Nicole (Simone Julia) - Her family is very rich. She has OCD. She is not fond of Putu. She does not like DK, as he is always following her around. She has been named the prettiest in class. She has two followers, Mary Jane and Bianca, twins. In the beginning of season 3, together with Ling Ling, she bought a café previously owned by Carlos.
• Kristof (John Packer) - He is impatient because Pak Budi's class often starts late, and he is always complaining. He likes Bu Rika.
• Irina (Irina Stroganova) - She likes animal and some kind of sports such as skateboarding. In season 3, she was accepted as the new waitress in Nicole and Ling Ling's café.

Season 1

• Aelke Mariska as Makoto, Kotaro's sister.
• Ayu Dyah Pasha as Pak Budi's mother.
• Ben Joshua as Pak Budi's stepfather.
• Imam Darto & Dimas Danang as themselves
• Melaney Ricardo as Bu Aya.
• Josephine Irene as Tina Kantina, Bu Kantin's niece.
• Niken Anjani as Sheila.
• Angie Ang as Lee's girlfriend.
• Sissy Firman as Tyson's girlfriend.
• Ahmedina as Mr. Arab.
• Acha Sinaga and Tora Sudiro as Toro and Wati.
• Dian Ayu as Chika.

Season 2

• Yeslin Wang as Mei-Mei, Ling Ling's sister.
• Darti Manulang as The Traditional Cake Seller
• Elkie Kwee as Ling Ling's Father
• Eddi Brokoli as Anton.
• Junior Liem as Kakata.
• Fanny Ghassani as Sukma.
• Masayu Clara as Ririen.
• Tike Priatnakusumah as Mbak Tike, a spicy chips seller.
• Hannah Al Rashid as Dennisse, the Bully.
• Mike Lucock as Pak Bowo.
• Gilian Panalewan as Ayumi.
• Alisia Rininta as Juni and Juli.
• Ana Oktarina as Putri.
• TJ as Mbak TJ, the Gangster.

Season 3