Kit Kat flavours in Japan: More than 300 flavours and one Australian wants to try them all

"I guess I've always been interested in trying weird and wonderful things. It was like 'check these out, these are crazy Kit Kats'. So I tried a bunch of flavours. I'd always liked [Kit Kats] beforehand."

Yuzu Koshu, a Japanese spicy sauce was the first flavour that struck a chord and to this day remains his all-time favourite.

"It was like a dark chocolate with citrus flavours and a peppery, kind of chilli taste."

Unfortunately for Butler, this Kit Kat was part of a limited-edition range and is no longer available.

"The things with Kit Kats is that some of them are seasonal and regional. Some have stuck around since I first tried them but others have appeared and disappeared."

Many of the flavours are only available in specific areas of Japan and are designed to showcase regional specialities.

In 2016, Hokkaido, famous for its fruit, inspired a mini melon and mascarpone cheese treat. Hiroshima's maple red bean cakes have also been incorporated into the Nestle range. A few weeks ago a red velvet Kit Kat to celebrate Valentine's Day hit the shelves with an estimated life span of just two months.

Shortly after learning of the Kit Kat craze, Butler packed his bags and left to discover more.

"I had just finished my PHD and decided I wanted to celebrate by climbing Mt Fuji and travel around Japan for a month. The Kit Kat symbolises what I like about Japan. It's just odd, in all the best kind of ways," he said.

After falling in love with the "weirdness of the culture", Butler returned twice more to continue his Kit Kat hunting escapades.

"They were harder to find than I thought they would be. I found train stations were often the easiest place to find them. Convenience stores tended not to have a huge range, but sometimes you would luck out and find a random flavour, like cola," he said.

Airports and food markets were the other best places as they stock more of the common flavours like chili, wasabi and sweet potato. Kit Kat Chocolatory Boutiques are spread across Japan and feature higher-end ingredients. Online stores have also started catering for international audiences as an affordable and convenient way to fuel the hobby without the plane ticket. "You can get the wacky flavours [online]. Six months ago, I got the sake one. They definitely taste quite sake-ish. You know what you're eating," he said.

After keeping a box of wrappers for record, Butler discovered his tastes were wackier then most. Soy sauce, wasabi, and pumpkin were among his top contenders. The maple pancake was a huge hit with family and friends. The fruit flavours, however, didn't score as well.

"They're pretty funky. A lot of the fruit ones don't work. Melon and pear are terrible," he said. Butler can't wait for his next Japanese holiday and has made loose plans to go over in 2020 with his wife for the Tokyo Olympics. Predictions for an Olympic edition have been made.

With Kit Kat resembling the Japanese phrase "kitto katsu" meaning "to surely win" the stakes are high.

Matt Butler's picks for the most unusual flavours

1. Edamame ... edamame (Japanese beans) is one of my favourite snacks. So are Kit Kats. So this should be a match made in heaven. WRONG.

2. Cola ... a great surprise. The fizzy cola granules between the wafers make for a different, yet delicious, Kit Kat experience.

3. Apple Vinegar (as well as Shinsu Apple flavour) ... apple should never be in chocolate, and this is no exception. The absolute worst Kit Kats!

4. Aloe Yoghurt ... the fact this is a collaboration between Kit Kat and Tokyo Beauty Clinic (TBC) should be testament to its oddness. Not horrible but not great either.

5. Carrot ... a seasonal Easter variation that mercifully has only appeared once and for a brief time. Veggies and chocolate are not a good mix.

6. Wasabi ... imagine what you think wasabi in a white chocolate Kit Kat would taste like. It tastes EXACTLY like that. Full wasabi flavour with a touch of the heat.

See also: 20 things that will shock first-time visitors to Japan

See also: The one dish in Japan you won't be able to eat

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