Their arrival sends ripples of excitement through Serang, a quiet hamlet fringed by rice fields and a volcano on Indonesia's main island of Java.
“The horse library!” children shriek, sprinting towards the mosque where Luna is tethered. Slung over her saddle are two handmade wooden boxes filled with books.
For many there, this unique mobile library is their only link to books. There is no traditional library nearby, and stores are miles away in big cities. It’s a problem for villages across the sprawling Indonesian archipelago.
Sururi, a 43-year-old professional horse groomer, devised a unique way to encourage reading in his district.
Armed with Luna, one of several horses under his care, and about 100 books donated from a friend, Sururi began road-testing his novel mobile library in early 2015, unsure if it would succeed.
It was a huge hit. In no time, the father of four was fielding requests from schools and villages further afield, eager crowds greeting him on arrival.
“The kids are always waiting for my horse and I,” Sururi said.
“Sometimes they even form a queue, waiting a very long time just to borrow a book.”
In Serang, enthusiastic youngsters flick through picture books, young adult titles and even some classics in English.
Some shyly pet Luna while waiting their turn to browse. Sururi believes the gentle nature of his six-year-old mare helps attract children, and pique an early interest in the books.
“The horse makes me happy," said 10-year-old Arif, who like many Indonesians goes by one name, before settling in to read a book titled “Wild Animals”.
But it’s not just children discovering a love for reading via this charitable community library.
Adults are almost just as enthusiastic, many pausing work and emerging from their homes as Sururi and Luna pass through the narrow lanes of one village.
Seventeen-year-old Warianti, perusing titles alongside her elderly mother, said villagers of all ages benefited from Sururi’s visits, as most did not have time to source books elsewhere.
“The horse library helps increase the knowledge of local women through reading,” she said.
Adult literacy rates in Indonesia have climbed steadily in recent years, reaching nearly 96 per cent in 2013, according to data from the ministry of education.
But some provinces remain far behind others. Central Java, where Sururi makes his rounds, is lagging in the bottom third nationwide.
Nearly five per cent – or close to one million – adults in this mainly rural province remain illiterate.
Sururi is aware of this, growing up in Central Java without access to a great deal of books.
But the altruistic stable hand never underestimated the importance of reading, leading to his free-of-charge mobile book loaning service.
“That’s the aim of the horse library, so that everyone can broaden their horizons, gain knowledge, become more intelligent,” he said.
Outside his simple home, Sururi has cleared an area where he dreams of building a permanent library, one stocked with many books and – perhaps one day – a computer.
But for now, everything is done by hand. The spines of all books are clearly labelled with a code for identification, and he keeps meticulous records so books are returned on time.
Like a conventional library, books can be borrowed free of charge but cannot be loaned forever.
In Serang, Sururi checks his notebook and tells one boy he needs to first return an outstanding title before loaning another. The young student sprints off home, returning a short while later clutching the forgotten item, relieved to see his pick of choice remains untouched on the shelf.
Once the flurry of borrowing is over, the children settle down in small circles, bearing their new books with pride as Sururi packs up for another week.
Soon the air is filled with the sound of dozens of children reading aloud, older pupils helping their younger friends with difficult words or phrases.
“When I see kids chasing my horse I feel so proud,” Sururi said.
“I feel like I’m needed, and that’s hugely satisfying.”