OSAKA, Japan—At the very last second, I learned that I had to eat the most expensive candies I'd ever bought in one sitting.

There may be pricier truffles and treats in this world, covered in gold flakes or disgorged from a goose's belly. But this was my highest-ever candy spend: $33 for a mere five Kit Kat bars... that had just been ordered to my customizations and doused in a bath of liquid nitrogen. (Add the costs of a trip halfway around the world and a four-hour transit journey to this brand-new, first-of-its-kind store, if you want to grow the price tag a bit.)

But this being Japan, I had to contend with a strange serving situation. All of the candy bars were presented on a single, paper-aluminum tray, not packed up to make the journey back home with me. So at this combined train station/mall complex, with nothing in the way of public benches, my only polite sit-and-eat option was in a cramped Nestlé shop, on a tiny red stool, and under gauche fluorescent lights while clerks shouted nearby.

By the end of my brief, supercharged candy feast, I didn't care one bit.

My recent vacation to Japan included plans to buy a bunch of Japanese Kit Kat as souvenirs, but I made a surprise revelation while I was overseas: Nestlé had just opened the world's first customized Kit Kat store, with an instant-freeze twist. That sent me on a candy quest I couldn't have predicted. And it indeed ended with me greedily devouring my overpriced haul, then wiping chocolate off of my end-to-end grin.

Some Ninja Turtles nonsense?

Before we get to the custom candy, I should clarify the burning Kit Kat passion that blew up an otherwise reasonable vacation day in Japan.

When I moved to Seattle 11 years ago, I was taken almost immediately to local outposts by my partner at the time. One of those was the Asian supermarket Uwajimaya, which I originally sought out because it sold durian, a notoriously spiky and stinky fruit from Southeast Asia that I happen to love.

While shopping at the latter, a pile of Kit Kat bags caught my eye. These things were covered in Japanese text... and they were bright green. Was this some Ninja Turtles nonsense I'd missed in the '90s?

I soon discovered that Kit Kat is a different beast in Japan, thanks to a "romance candy" marketing campaign and a diverse flavor rainbow. The store's bars were green tea-flavored, and they benefited as much from that atypical flavor base as from Nestlé's superior chocolate-sugar mix. (Turns out, Hershey's produces the snack in the USA, and the results taste worse than Nestlé's international formula. Hershey's actually makes import shops slap a label on Nestlé Kit Kats informing consumers that they're different. Which, as far as I'm concerned, is a point in Nestlé's favor.)

I've since sampled a variety of weird Japanese Kit Kats either sold at Uwajimaya or brought back from friends who've traveled abroad. Fruit-flavored, cheesecake-inspired, matcha-rich, nut-topped, or intended to be zapped in a toaster oven: gosh, they're just the best. A perfect size for a sweet (but not too sweet) bite; a quality combination of velvety chocolate base and crispy wafer; easy to share with a friend or loved one; and far more ambitious with flavors than any wrapped American snack.

This love affair with Kit Kat played no small part in my Japan travel plans. I made space in my luggage specifically so I could bring piles of Japan-only candy back home with me. (I purchased roughly $70 of boxed and bagged Kit Kat during my two-week vacation. One collector's package I purchased, full of "strawberry cheesecake" bars, comes in the shape of Mt. Fuji.)

An anxiety-ridden, four-hour train journey

On Wednesday, October 16, Nestlé of Japan opened the doors to a brand new "Chocolatory" shop at a major Osaka transit hub. Days later, I got my inspiration from a Japan travel-tips forum thread at the gaming site ResetERA, where one member linked to a news report about the shop with a simply stated question: "Who here is going?" I heeded the call.

The article was scant on information, however, and Nestlé hadn't made any announcement of its own. Visits to the official Chocolatory websites included no mention of this Osaka shop, which ensured that my four-hour trip was riddled with anxiety. Thus, I bee-lined to the informational map at the Namba Station in Osaka, which includes multiple train companies' lines and a bustling mall, in search of something that said "Nestlé," "Kit Kat," or "Chocolatory." I found nothing. Thankfully, an information desk attendant put two-and-two together after I rolled out every brand-name buzz word I could think of. She handed me a map, circled an elevator icon, and told me to go to the building's second floor. (This map didn't have a second-floor diagram of any kind.)

This floor has a much smaller square-footage of shops in front of one of the station's many train turnstiles, and sure enough, one of those is a Nestlé Chocolatory shop (typically dedicated to Kit Kat gift boxes). On that Sunday, a few clerks were stationed by the door, barking something over and over in Japanese while gesturing to signs about customized candies.

The front of the shop is dedicated to Nestlé's Nescafé line of coffees, which is distracting enough. There's even a robot that asks questions and takes coffee orders, but it's pretty rudimentary. The star of the shop is against its back wall: a station that looks like something out of a standard ice cream shop, with "toppings" that are scooped out of aluminum trays.