Japan has no shortage of great whisky bars. At dekantā, we have visited more than our fair share over the years, but Bar Ozawa in Karuizawa remains one of our favourites.

Upstairs on a side street near Karuizawa Station, Bar Ozawa is small, intimate and easy to miss. It's also worth mentioning that booking ahead is mandatory. The bar has only a handful of seats, but that’s part of what makes an evening here so enjoyable.

We've visited several times, and there is always something familiar about walking through the door and finding Ozawa-san behind the counter. He is a rather quiet man, always impeccably dressed and completely professional. But ask him about a bottle, a producer or some piece of Karuizawa's history and he’ll be generous with his knowledge. He has spent a lifetime around great whisky and great hospitality.

There is also a wonderfully social side to the bar. You might be sitting next to someone you've never met, and by the end of the evening you’ll leave with a new pal. We've more than once arrived as strangers and left feeling like friends.

Then there are the little details. Depending on the season, Ozawa-san will present unbelievably delicious fruit (we had strawberries in spring) and always a dish of tiny chocolate cubes he’s attractively arranged by colour. There’s no rush in his bar - but you’re never left wanting either.

Before Bar Ozawa, Ozawa-san spent almost four decades working at the legendary Mampei Hotel in Karuizawa. Founded in 1894, the hotel is one of the defining landmarks of the town, tucked away among the trees of Sakuranosawa. Its distinctive Alps Wing, completed in 1936, is a beautiful wooden Western-style building, with dark timber, classical detailing and a distinctly old-world atmosphere. Inside, the lobby is filled with warm wood, stained glass and artwork, while red carpets and velvet curtains give the hotel's bar the feeling of another era. The whole place feels deeply connected to the Karuizawa of the early twentieth century, when the town was becoming one of Japan's great summer retreats.

Ozawa-san joined the hotel when he was just 20 years old and spent almost four decades behind its bar. During which he found himself at the centre of a story involving John Lennon and a cup of tea.

When Lennon was staying in Karuizawa with Yoko Ono and their young son, he would regularly visit the hotel's Café Terrace. One day, he asked for a “milk tea.” The drink the hotel served wasn't quite what he had in mind, so Lennon showed the staff how he preferred it to be made. Ozawa-san was the member of staff who prepared it for him.

Rather than brewing the tea first and adding milk afterwards, Lennon's method was to heat the milk and steep the tea leaves directly in it. The result is a much richer drink, with the tea and milk infusing together rather than remaining separate.

That simple request eventually became one of the Mampei Hotel's signature drinks: its famous “Royal Milk Tea.” The version served today is supposedly richer than Lennon’s, and is finished with whipped cream, but its origins can be traced back to that encounter.

The bar is very well stocked with both Japanese and international whiskies, and Ozawa-san has an impressive knowledge of what is on the shelves.

On our most recent visit, he showed us two original Karuizawa bottlings, both signed by Nakazato-san: one 22 years old and another a mighty 40 years old.

There is something particularly fitting about finding bottles like these at Bar Ozawa. Karuizawa's whisky history is often told through old bottles, distillery records and auction prices. At Bar Ozawa, it feels much more personal. The history is sitting behind the counter, and some of it is being told to you by someone who has been part of Karuizawa's story for decades.

For anyone visiting Karuizawa with an interest in Japanese whisky, Bar Ozawa is well worth seeking out. Come for the whisky, stay for the stories, and leave with new friends.