"I feel like I am in a funeral," 28-year-old Duanghatai Boonmoh said with a laugh as she sipped a chocolate "death smoothie" on a recent Saturday afternoon.
She and other curious customers took turns climbing into the wooden box as friends sealed the lid.
The cafe's owner says his restaurant is more than just a gimmick or dark take on the cute and cuddly coffee shops common in the Thai capital, which boasts everything from cat, husky and meerkat cafes to unicorn and mermaid-themed eateries.
A professor and social researcher, Veeranut Rojanaprapa launched the cafe as a way to teach Thai people - some 90 per cent of whom identify as Buddhist - about the benefits of "death awareness".
"We found that having an awareness of death decreases greed and anger," explained Veeranut, whose giggly demeanour belies his fascination with more morbid matters.
He believes the Buddhist concept, rooted in ideas of impermanence and selflessness, is the key to ridding Thai society of chronic problems like violence and corruption.
"When one is aware of their own death, they will do good. This is what our Lord Buddha teaches," he explained.
The casket experience is also a way to nudge the country's technology-addicted youth to step back and reassess their personal lives.
"When teenagers go down to the coffin and our staff close the coffin, because of the darkness, because of the small space, they will be aware of themselves... they will recall the things that they still haven't done," said Veeranut, adding that he makes a point of considering his own demise nightly.
The professor is not the first to offer a resurrection experience in Thailand, where a temple outside Bangkok is famous for hosting symbolic funerals for devotees looking to clear their souls of bad karma.
But his cafe and coffin sit squarely in the middle of a local community centre in northern Bangkok, offering a public - and morbid - reminder of mortality that not everybody in the neighbourhood is happy about.
The cafe has also spread out to a public walkway, which is now posted with signs asking questions like: "What is the purpose of your life?"
"This is so disturbing. I feel really strange walking there and might avoid this shortcut," one person wrote on a neighbourhood Facebook page.
Yet Veeranut says he welcomes any controversy as a sign of success.
"I love all of the complaints. Because if they are complaining it means they are thinking about death, they are aware of death."
