Tokyo is the door to Japan — a door that can hit you on either the way in or out, if you don’t come prepared.

For there is much to see and do, and the casual traveler can easily get bumped astray in the maze of options.

Yet a Google here, a Google there and all the sights of the Kanto Plain can soon be sewn together into one lumpy Frankenstein of fun.

“Where to go and what to do”! “Tokyo from A to Z”! “Tokyo inside out”!

Online, one can quickly find lists of attractions, but you will not find there what I will now offer you here: a short list of where you shouldn’t go and what you shouldn’t do — plus, when you shouldn’t do it.

Here it is: Tokyo — all the must-miss spots that might ruin your day, if not your entire visit.

When not to go

1. Golden Week

From late April through the first week of May is when all 40 million Kanto residents have free time. Remember the tight line of people filing off your plane when you arrived? Triple that and then add an army of squirming, squealing kids. That’s what you’ll get at any Tokyo-area attraction during Golden Week, when the only thing you will really see are the crowds.

2. August, especially mid-month

The o-Bon summer holiday period is similar to Golden Week in that everyone has free time and all sights will be vacuum-packed. Plus, school is out the entire month, meaning kids — lots of kids — everywhere. And if that won’t make you sweat, the temperature and humidity will.

3. Any holiday, except New Year’s

Unless you enjoy being a sardine.

4. New Year’s

Here the problem is not crowds but closures. Outside of shrines — which will be boiling with visitors — most sights will shut down for the first days of the year. The good news? You will get a seat on the train and at restaurants, too — if the one you want is open.

Where not to go

1. Tokyo Skytree

Which dominates the city skyline from any spot on Tokyo’s northeast. So why go there, especially when the view from afar is arguably more breathtaking than from the worm’s-eye vantage below — an angle you will have to share with a million other worms? You can also worm your way to one of the observation decks — that is, if you want to invest hours in waiting your turn.

2. Shinagawa Aquarium

Which typically has more visitors than fish, with many of these visitors pressing themselves wide against the aquarium glass with their cellphone cameras to take photos. I can see how one shot of a fish might be nice (if you can catch it smiling), but do you need shots of every fish in the pool?

Unfortunately, some people do. The aquarium highlights are a tunnel-style tank, which, if not crowded (ha — the fish all smiled at that), can be strolled through in 30 seconds, and a shark hall, which is not a hall but a corner. A tight corner. With two sharks.

3. The Imperial Palace

Which stands beyond public view. What you will see instead are some stony walls, a moat and maybe a drifting swan.

You will not catch the Emperor posing for photographs, unless you come on his birthday or the second day of the year. On those occasions he offers short greetings to the crowds, which are herded along at regular intervals. But even then, your only photo op will be of a windowed balcony, perhaps not unlike an aquarium.

At other times, guided tours are available — if you reserve in advance — but there is no English and the guide is not the Emperor. The adjoining East Gardens are open any day, but as gardens go, this is sort of like meat loaf: You can find better fare elsewhere.

4. Tsukiji fish market

Here the fish do not smile. They’re dead. But, yes, they are all around. So, if you want multiple shots of lifeless sea creatures, this may be for you — if you do not mind all the bustle, the early viewing time and the smell.

Otherwise, just go to the fish section of a ritzy supermarket, where you will find a cleaner, albeit smaller, version of the same thing, only at a more reasonable hour and with a better chance of free samples.

5. Beer Museum of Yebisu

Entrance is free but the samples are not, which is all you need to know about a beer museum.

6. Kanda-Jinbocho “Book Town”

Why would any tourist spend even one long yawn looking through the fabled (and almost entirely Japanese) bookstores of Kanda? If you are after books, then go to the big boys — Kinokuniya, Maruzen and so on — where you might even buy a guidebook, which will also offer plentiful choices of what to see.

But as to the spots above, be wise and let the door swing closed.

When East Marries West appears on the fourth Monday of the month. Comments and ideas: community@japantimes.co.jp