Locker/luggage storage Shinagawa Station

On our final day in Tokyo (30/3, Sat) - 5 of us will take the Yamanote Line from Kanda to Shinagawa Station. Then leave our large luggage (5 pieces) at Shinagawa. Go to places like Naka Meguro etc. Back to Shinagawa Station to catch the Keikyu Line to Haneda around 8pm.
I�fve tried finding manned luggage storage but there is one which closes early. As for the lockers they all seem to be inside the ticketed areas. What do you recommend?

Here a link(Japanese) on coin locker outside ticket gate at Shinagawa Station.

Whether it is convenience or not ..

https://coinlocker-shiori.com/jr-shinagawa-station/

2 outside the Shinkansen ticket gate, 2 outside the Konan exit,

Thanks so much for the link. I google translated it and the details are very helpful.
Can I however check 2 things.. As I mentioned, we would be arriving Shinagawa by Yamanote Line. Store our luggage at a few large lockers then return after dinner to collect luggage and take the Keikyu Line to Haneda.

1. The article mentioned if the lockers are all full there are more inside the Keikyu Line ticketed area. Is it possible for us to enter the Keikyu ticketed area to find the lockers then go out again - Returning later to ride the Keikyu Line to Haneda? How does it work?

2. Also, I study the Shinagawa Station layout. The transfer gate to Keikyu Line is inside the JR Central Ticket Gate. Does this mean if I store the luggage within the JR Central Ticket Gate, upon my return I can enter the Central Ticket Gate, collect the luggage then enter the Keikyu Ticket Gate (with the Keikyu ticket)?
By storing our luggage inside the JR Central Ticket Gate, how much does it cost us to go in to retrieve our luggage? Or is this settled if by then we already holding the Keikyu tickets?
Here is the link to the Shinagawa Station Layout: https://www.jreast.co.jp/e/stations/e788.html

Oops.. Forgot to mention - we will use IC Card to take the Keikyu Line to Haneda.

I might suggest this since you are flying out of Haneda anyways...


...why not just go all the way to Haneda (only another 15 minutes beyond Shinagawa on Keikyu line) and a) just check your luggage in to the airline that you will be flying or b) use one of the JAL or ANA or other luggage storage services at the airport terminal?


Why do I suggest this? It is hit and miss whether you can find not just luggage lockers but ENOUGH luggage lockers that can hold ALL of the pieces of luggage, particularly large pieces, that will be available for you at that day and time. It is very hit and miss with lockers as many people use them for day storage.

Sure, it takes a little longer to get to Haneda however, on the flip side, your luggage is already there and already either checked in to the airline or available at the luggage storage counters.

My two cents.

Stan