Luggage in Tokyo Station

Basically I need up to date information.
I will be staying in Tokyo for 3 days, And I want to know if there is a place that they store luggage.

So a manned warehouse, in the basement, where you take your large luggage and store it in there till you return.

Ideally one I can leave the luggage there for 7-8 days, and incurring a small fee of 500 yen.

Please let me know if anyone knows if there is such a service. I plan to get a large suitcase when I get to Japan, at some point.

impossible.
Also coin lockers limit not so long.
(large/super large size 500Y and more/day usual)

So HRD recommend 2 weeks max.
http://www.haneda-airport.jp/inter/en/premises/service/delivery.html
(fee : per day)

http://www.tokyoinfo.com/guide/faq/faq004/faq011.html
http://gransta.jp/service/cloak.php

Can someone tell me if these are overnight or not, The Google translate makes no eligible sense unfortunately.

http://www.tokyoinfo.com/guide/faq/faq004/faq011.html

There was a second section that mentioned 15 days.

the second section you cited:
◆レール・ゴー・サービス
営業時間：8:00〜20:00
電話番号：03-3231-0804
料金：1日1個につき420円（6日目からは１日1個につき840円）
※お預かり期間は最長15日間です。

max. stay is 15 days.
420 yen for one per day during Day 1 to Day 5(4 nights).
after Day 6, 840 yen for one per day up to Day 15.
calculation
7 days(6 nights) = 420x5 + 840x2 = 3780 yen for one baggage.
the prices seems to be old(5% tax ?, or tax not included). you may need pay more.

How about TA-Q-Bin?

http://www.kuronekoyamato.co.jp/en/contact/faq/02/

Please refer to Q02/A02.

Thanks for the translation, I will check it out, Ideally I shouldn't have anything to store, And I would only have a cabin bag till I return to Tokyo, where I plan to get a luggage in Ueno.

Can anyone tell me if that shopping street district ame.... something still sales cheap large luggages?