With eyebrows furrowed and small fingers wrapped around a pencil, the boy traces English words on his book.
He fidgets a little in his seat as his feet cannot yet reach the floor. He is, after all, just five years old. Behind him, primary school pupils about three years his senior call out the English equivalent for various Thai vowels.
No one, it seems, is too young for private tuition at Kru Ou English School in Thailand's Mahasarakham province.
This is more than 400km from Bangkok, where students crowd tuition school chains on weekends in the hope of getting a foot in its most elite institutes. It is located in Thailand's north-east, which remains the poorest region in the country despite recent expansion of household incomes.
But Kru Ou school has tripled its number of students to 300 since it opened in 2010, as parents nationwide fret over slipping standards in the mainstream Thai education.
Kru Ou ("kru" means teacher in Thai) is Ms Atchara Latham, a 30-year-old English major graduate from Mahasarakham University who started the school after returning from the United States, where she picked up English teaching skills while working as an au pair, or domestic assistant.
"I want to make my pupils as confident as the American kids," she tells The Straits Times.
The slim, attractive young woman has more than a decade of English teaching experience under her belt, starting from when she was 16 and had to give tuition to supplement her family's income.
Over the years, she has starred in a few karaoke videos featuring easy-to-sing English-Thai songs and is milking this recognition by using blown-up photographs of herself as billboards. These larger-than-life images, framed by the words "I love English", greet students as they step into the lobby of her three-storey school.
The "I love English" phrase is also printed on the school's tote bag and T-shirt, which are given to all students for free.
Walls of its six classrooms are covered in a riot of bright yellow, pink, blue and purple, while a replica of an airport display board spurs students to set their sights beyond Thailand.
Endu, the resident golden retriever, noses up to kids in the lobby, where cushioned stools beckon to students wanting a snack and a chat.
It feels like home, but everyone means business.
Elementary lessons held twice a week cost 1,100 baht (S$44.60) a month. Lessons start in late afternoon - after work, school or, in some cases, kindergarten - and can end as late as 10pm. The school operates every day and Ms Atchara, who is aided by six other teachers, works just as regularly.
The mostly middle-class students compete for scholarships to attend summer camps in Britain, the United States, Australia and Singapore.
Thirteen-year-old Mahinthorn Pothiwan tells this reporter he wants to be a businessman because "I want to be rich; everybody wants to be rich".
Ms Atchara declares that the school has grown without much advertisement - save for some flyers she distributed when she first started three years ago. Every month, though, the school organises a "movie day", where students head out to the local cinema together dressed in its signature T-shirt. The garment is printed with the Facebook address of the school. Inevitably, curious parents come a-knocking.