In the village of Serang, in the hilly, rural Purbalingga region on the edge of Mount Slamet, one man and his horse are the essential links between separate communities.
They are Pak Ridwan Sururi and Luna.
In January, Pak Sururi began travelling between villages with books stored in boxes stacked on Luna's back.
They visit schools three times a week, and sometimes he brings along his daughter, Indriani Fatmawati.
The villagers and children don't have to pay to borrow books and Pak Sururi has not looked to make money from the scheme, saying,
"I love horses, and I want this hobby to bring benefit to people."
The idea for Kudapustaka came from Nirwan Arsuka, a fellow horse enthusiast and friend of Mr Sururi's. "He asked me: Can we help society through our hobby? I said I was interested, but I didn't know how."
"Then, he had this idea to create a mobile library using horses. I liked the idea, but sadly I didn't have any books. So, he sent me boxes of books."
Indonesia has made great strides in reducing adult illiteracy. From 15.4m unable to read in 2004, that number has fallen to below 6.7m. However, there are still almost 1 million illiterate adults in central Java alone.
It is this region, Ridwan and Luna's home, that they wish to help.
Since he looks after horses for a living, Ridwan doesn't own any of his own animals. Did he ask permission to borrow Luna?
"I haven't (he says, laughing)... The owner lives far away from this village and hasn't visited the horses for a long time. I am a bit sad about that."
"It was a wild horse, but I tamed it. Luna has never kicked or bitten anybody, and is very friendly when surrounded by children."
Like any library, it could always add more books to the collection, and Pak Sururi wishes more people would donate books to the scheme.
"Children here love comics and story books"
"Adults, on the other hand, need inspirational and how-to books, like how to farm, that kind of thing."
Mr Sururi dreams of one day owning his own Kudapustaka horse - and a real library too.
"I hope I can have a small library in front of my house," he says. "But I know it is only a dream."
For more information on how to help Ridwan's dream come true, check out the Kudapustaka Facebook page