When to arrive after/during Golden Week 2018?

Hi there peeps.
I am planning on visiting Japan in 2018 for 3-3,5 weeks. I was planning to go during summer at first but as it appears a bit too warm for me, I was aiming for April or May. More of my interests seemed to be open during May however so I ended up deciding to go to arrive somewhere in late April or early May. Not really sure when would be best to arrive though.

I have the possibility of arriving in Tokyo, Osaka, Nagoya or Fukuoka. I suppose Tokyo is the busiest.

The Golden Week ends 6th of May, I suppose people are returning to Tokyo and other places by the end of the day. Would arriving on the 6th or 7th be a hassle? Or arriving a few days earlier than that?

I am not sure where to head yet as I still are planning what to do and where to stay. But first off I must decide on an arrival date...

Unless in the first few days, i.e. still during GW you plan to move within Japan, I think you can chose any of the place for your first landing. Yes Tokyo is a busy airport, but they are well organized (as everywhere else in Japan), so I would not be worried about arriving in Tokyo right at the end (or in the middle of GW). Once you have arrived at Tokyo the only thing you need to do is catch a train to your hotel and that is always possible, including in GW.
So my advise would be to book either the cheapest flight, if you have no clear idea where you actually want to go, or to book one where you can change the landing point at a later stage, once you have planned your travel. Or is this questions right now only about when to ask for leave from work? Frankly, I probably wouldn't book the flight until I have a fairly clear idea where I would like to go, so the flight makes sense.

Enjoy your trip to Japan!

Thank you very much for your reply :)

Actually I have been to Japan before but last time was in the month shift of March-April. The amout of people was... quite a lot. In Kyoto the sakura was in full bloom and had to push through hoards of people and loads of people on the train to Arashiyama for instance. It was not really fun.

I also wanted to go to see the peninsula near Aomori as well.

I fancy the city of Fukuoka too so I thought of maybe going directly there (it would save the time of going by train or domestic flight).

I would like to visit Kyoto, perhaps the alps area (Tateyama?), Takayama, Tokyo, Kanazawa, etc. Perhaps some of Tohoku area and more of Shikoku.

Some major sights have already seen, like Osaka, Kyoto (still some to see though), Nagoya, Nikko, Okayama...

I was thinking of going to Sapporo but maybe it is still too cold up there?

Since traveling distance from Tokyo to Fukuoka or Shikoku is quite long, I am still not sure about using Tokyo as a base. It is good for Tohoku (and perhaps Hokkaido) as well as Kyoto possibly, Kanazawa, maybe Takayama but going longer would mean a day long of travel or domestic flight (which I try to avoid for the budget)...

Osaka airport was nice, good and cheap connections as well. Works better for Kyoto, Takayama, Kanazawa, etc. Shikoku, maybe Fukuoka.

Nagoya not sure, of course better for the alps area and so.

I was thinking of checking out Okinawa or Ishigaki as well but if it is rainy season, maybe not...