This is a family/relationship issue, travel just happens to be the immediate cause of the problem.

Perhaps tell your sister "No" about all those other people, but you and your sister don't have to tell them anything (yet). Like some previous posters (and you yourself) say, the situation might never happen.
Just keep on planning your trip with your DH, your sister, and her DH. You are four people going on a trip.
And don't talk about the trip to those other people. Not until you are home again.
Happy travels!

Anonymous wrote:

I'm getting the impression that they want me to play tour guide and that's not how I want to spend my vacation.

Why is venting and stressing preferable to managing expectations. I don't understand this. I'll never understand this.

wants to see a real sumo match (fine, but that doesn't interest me

Alright, OP completely lost me on that one.

The sumo tournaments in Japan happen only at certain times of the year and it's not during the time we are there. You can book touristy 'fake' ones though like Get You Guide set up just for tourists. Not interested in that.

No is a complete sentence.

I'm getting the impression that they want me to play tour guide and that's not how I want to spend my vacation.

Why is venting and stressing preferable to managing expectations. I don't understand this. I'll never understand this.

wants to see a real sumo match (fine, but that doesn't interest me

Alright, OP completely lost me on that one.

Anonymous wrote:

Anonymous wrote:You're working yourself up for a situation that hasn't happened. There are a ton of times family or friends have made remarks about joining us on vacation but never follow through.

This. I don’t see anywhere in the op where they ask you to reserve plane tickets or hotels or events for them. I doubt it will come to that honestly. The less you challenge the less likely they’ll get their acts together to actually follow you. It’ll all fall apart against once it comes time to book tickets, hotels, etc.

Saying no would be like a throwing a challenge.

OP here. Yeah, I know there is a huge possibility that it will ever come to fruition - especially with the BIL because he seems a bit flakey, but her ILs are more likely to follow through with this because they've been wanting to go on a trip with my sister and her husband for a long time now. They were all about planning a trip to Europe to see a bunch of Christmas markets last year but no one followed through and started planning so it all fell apart. I worry because this is a trip that's already planned so everyone can be lazy about it and get their plane tickets and expect me to do the rest, which I don't want to do. Even 6 people, I don't want to do this. But yeah, hasn't happened yet.

Anonymous wrote:You're working yourself up for a situation that hasn't happened. There are a ton of times family or friends have made remarks about joining us on vacation but never follow through.

This. I don’t see anywhere in the op where they ask you to reserve plane tickets or hotels or events for them. I doubt it will come to that honestly. The less you challenge the less likely they’ll get their acts together to actually follow you. It’ll all fall apart against once it comes time to book tickets, hotels, etc.

Saying no would be like a throwing a challenge.

In my experience people who want to tag along are all talk. When they start making noise about joining my trip I tell them the dates and say I'm happy to meet them for dinner and drinks while we're there, and I leave it at that. Once they realize I'm not playing travel agent or tour guide their interest dissipates.

No, no, no under any circumstances. Shut it down immediately. They can plan their own trip.

Eight people sounds like a nightmare.

Your sister should convey to them that it’s too many people for a trip for coordination purposes.

You're working yourself up for a situation that hasn't happened. There are a ton of times family or friends have made remarks about joining us on vacation but never follow through.

I agree with PP - tell them no, but that you will gladly share your itinerary with them when you return so that they can plan their own trip for a future date.

+1 I would also die on this hill. The trip sounds like it would become a disaster with these extra people.

I would tell my sister no, immeditely, right now. She should tell all those other people that her sister (you) planned this trip for the four of you, so it's not her trip to invite other people. But she'll happily help them plan another trip later for everyone to attend.

Do not let this happen, OP. This is a hill I'd be willing to die on.

Basically just venting because this hasn't actually happened yet, and there's definitely a possibility that it won't come to fruition at all.

So I have a trip to Japan planned for this fall - first time there. It'll be myself, DH, my sister and her husband. I travel with my DH a lot, and I also take lots of trips with my sister, but this is the first time I've traveled with 4 people - but it should be fine, my sister's DH is very easy going and we all get along really well. This is a 2.5 week trip.

But now more people want to tag along. Specifically, my sister's inlaws got wind of this trip and want to come. And potentially her BIL and his wife. I don't really know these people that well, I only met them once (they all are scattered across the country!). My sister told me this and she's definitely NOT keen on this idea, but is hesitant right now to flat out say no. She saw all this in their group chat and they want to tag along and 'follow us around Japan' because it's all planned and 'sounds like fun and 'your sister (me) sounds like she plans great tips.' The BIL says he wants to see a real sumo match (fine, but that doesn't interest me, he can book it himself).

This is possibly 8 people now!! This sounds like herding cats. For one, I planned this entire trip myself with absolute minimal input from my sister and her DH. My sister has a similar travel style to my husband and I, so I don't really mind because if I like something, she probably likes the same thing. Our plane tickets are booked and coordinated, so that we are meeting in SFO to take the same flight over to Tokyo, and vice versa on the way back. All airport transportation is arranged for the 4 of us when we are in Japan, hotels are booked, I have one private tour booked (that is a max of 6 people) and I have a rough itinerary of what places in Japan we will be traveling to. This would now involved coordinating more airport arrival/departure times, hotel rooms, re-book the tour, etc. We have plenty of time as the trip isn't until late fall, but still. This was a lot of work on my behalf - watching youtube videos, social media stuff, google research, etc.

Only 3 of us have traveled internationally before (myself, DH and my sister). The rest haven't been outside of the US.

And then managing getting 8 people getting through chaotic train stations, crowded streets, coordinating meals. JFC.

Not that we all have to stick together the whole time, but I'm getting the impression that they want me to play tour guide and that's not how I want to spend my vacation. I don't care if they want to come to Japan around the same time as us but I do not want to move around all my reservations and plans. 4 people is plenty to travel with. I don't think I can handle 8.