Stay in Tokyo and Yokohama or either?

Hello :)
Me and my fam (total 4 person) are going to Japan this late November. We are planning to explore Yokohama for 3D2N and move to Tokyo for a few days (maybe 3 nights). Which one sounds better:

Staying in Yokohama then move our stay to Tokyo,
or
Staying in Yokohama OR Tokyo, and having a round-trip since these two cities are close?

At first i thought staying in either Yokohama or Tokyo is a good idea since we don't need to move our big suitcases twice and Tokyo-Yokohama is only around 30 minutes, right? (and the last time i checked from google map, the ticket for one trip by train will cost around 200yen per person, still affordable tho)
But i did some reading on forums and the main problem for round-trip Yokohama-Tokyo is packed train in busy hours (at 7.30-09.30 am if i'm not wrong?).

So what do you think? We need your advice.

Thank you very much!

They are around 25 minutes apart. I don't see the point in changing hotels

I live in Tokyo but I sometimes stay in a hotel in Yokohama for a few nights, just because it's more relaxing to have a leisurely dinner and go back to your hotel versus traveling for an hour at the end of the day.

But I also want to point out that Tokyo has about 100 times as much to see as Yokohama does. You might find that one day is enough to see all there is to see in Yokohama. I don't have children though, so that might change things. Here are some things to do in Yokohama including activities for kids; you can decide how long to spend: http://whereintokyo.com/dbinx/ra-yoko.html

In all probability I would stay in western Tokyo anywhere on the Yamanote line to avoid the day spent shifting hotels. I normally book a breakfast at the hotel & have a leisurely start so by the time I'm ready train overcrowding isn't too bad. If you are heading towards Yokohama you would be going in the opposite direction to the heaviest rush anyway.

I live in Yokohama and my family members commute to Tokyo on a daily basis. I was going to suggest the "Staying in Yokohama OR Tokyo, and having a round-trip" option until I saw that you're concerned about "packed train in busy hours (at 7.30-09.30)".

What do you plan to see? Do you really need to ride trains during 7:30-9:30? Typically, tourists (both domestic and foreign) stay in one place within Greater Tokyo, enjoy breakfast, and then hop on a train for sightseeing no earlier than 10:30. Besides, many of the shops and museums don't open until around that time.

The city/area you stay in also depends on your preference. Perhaps you can get better answers by providing a rough itinerary and what kind of hotels you usually like to stay in.

Between Shibuya and Yokohama and Shingawa and Yokohama are not busy in the direction of Yokohama in morning peak.

hello! Thank u for your replies..

We actually haven�ft set any plan yet in Yokohama.. the only thing is certain is Chinatown since we want to visit our relatives there.

I will discuss to stay in one place only to our parents then. Thank you for you advices! I am very excited to visit Japan again :)
Hope u guys have a good day!

Chinatown is accessible from either the Toyoko Line or the Negishi Line, depending on what part of Chinatown you frequently want to visit.

For the former Line, you will find accessible and nicer hotels near Shibuya Station in Tokyo. For the latter Line, you will find accessible and nicer hotels near Shinagawa Station in Tokyo.

In any line, last trains leave around midnight. So in addition to what others have suggested, you may want to choose the city you stay in depending on how late you want to be awake in that city. For example, if you stay at a hotel in walking distance from Chinatown, you can spend time with your relatives without worrying about missing your last train (a taxi to Tokyo would cost you a small fortune). But if you're going to bed early anyway, you may as well stay in Tokyo if you want to do most of your sightseeing there.

There are also dozens of "business hotels" along the route, if you plan to use taxis more often or if you choose to see more things in between Tokyo and Yokohama.