A Sydney bookstore has told a dating coaching company to stop sending clients to practise "pickup" techniques on its customers.

The Japanese-owned bookstore in Sydney's CBD, which claims to be the largest in Australia, issued an open letter to customers on Friday.

"It has come to our attention that a dating coaching company has been using our store to give their clients practical experience, much to our dismay.

"To anyone who has felt harassed we offer our deepest apologies.

"We have contacted the company we know is involved and requested they not enter the store again."

Kinokuniya, which chose not to name the dating coaching company responsible, warned other companies against trying a similar thing. "Don't come in," the open letter said.

"Our staff and security have all been made aware that this has been happening and are on the lookout for anyone who is receiving unsolicited and unwanted attention."

Dating coaching services offer to teach men who are unsatisfied with their dating life how to meet women and start conversations, but their tactics have been criticised for being manipulative, sexist and insulting.

Writer Chloe Sargeant said a man came up to her while she was browsing at Kinokuniya last week asking for book recommendations.

"I had seen him walking around the store for a while, and he had spoken to two women before me.

"He followed the 'lines' and language from 'The Game' and other PUA (pickup artist) stuff word for word, and stood really close to me, despite me trying to step back repeatedly."

She suggested he read feminist books such as Fight Like a Girl by Clementine Ford and The Power by Naomi Alderman.

"He seemed flustered by this, the conversation quickly ended."

Pickup artistry became well-known thanks to Neil Strauss's 2005 bestselling book The Game, which detailed techniques such as the art of "negging", an emotional manipulation technique where insults are used to undermine the self-confidence of the target to make them more vulnerable to an advance.

Ms Sargeant said she appreciated the response of the bookstore.

After she tweeted about the experience, a Kinokuniya employee reached out to check she was OK.

"It was a gross and bizarre experience, but no amount of creepy pickup artist dickheads will keep me from my favourite bookstore."

Hilary Locke said she had also been approached.

"I just thought it was some random moment. I'm so glad it's been addressed and hope it gets nipped in the bud," she posted in response to Kinokuniya management's message.

"It's reassuring that it wasn't just me in a way, but at the same time sad that others have had that experience while just browsing books."