SIM-card(s) for 21 days

Hello,
My partner and I will arrive in Osaka/Kansai Airport next week for a 21 day trip to various places on the Southern part of Honshu Island.
Having read the (complicated!) information about SIM-cards for visitors, we are confused and various questions remain unanswered.
Our local Osaka friend recommended us to buy an NTT card for better coverage while we are in the Japanese Alps. It should be bought on Kansai Airport.
Our questions:
1. Is it REALLY true that there are no reasonably priced SIM-card of any provider for VOICE for tourists?
2. It seems NTT only has 7 and 14 day plans. How if we want 21 days? Can each of us buy a 7 AND a 14 day card - in other words: can the 14 day card be validated on day 8? Or does the validity of each card start on the date of purchase?
3. Is there no option to top-up a card?
4. Is it true that at the end of use the SIM must be returned? Can that be done on the same Kansai airport upon departure?
Thanks for your information!
Greetings,
Wim/Indonesia

Almost all Prepaid Data SIM are leased from NTT Docomo.
So in term of coverage, it's all the same while speed can vary depend on SIM company.

Some Prepaid SIM can be ordered online and delivered to your hotel/address or Airport Post Office.

1. Is it REALLY true that there are no reasonably priced SIM-card of any provider for VOICE for tourists?
Yes, mostly true. SIM with Voice normally require proof of Japanese residency. Only option will be rental but very expensive compare to data only SIM.

2. It seems NTT only has 7 and 14 day plans. How if we want 21 days? Can each of us buy a 7 AND a 14 day card - in other words: can the 14 day card be validated on day 8? Or does the validity of each card start on the date of purchase?
SIM card usage start once you activate the SIM. So, yes, activate 14 days SIM on the 8th day.

3. Is there no option to top-up a card?
Some SIM do offer Top-up credit, but normally require credit card purchase.

4. Is it true that at the end of use the SIM must be returned? Can that be done on the same Kansai airport upon departure?
Depend on the SIM provider. Some company require SIM to be return, some not.

There are some prepaid data SIM available for resident that have same plan and price but valid upto 30 days. Ask your friend to check at Bic Camera or Yodobashi, or Amazon.
http://goo.gl/uSH7JZ

Some prepaid SIM:-

bmobile PAY G SIM Data and Voice
7 days , 60 min. talk and 3GB
Require user to send passport picture for SIM activation
RRP : 9,800yen
http://www.bmobile.ne.jp/payg_sim/product.html

others bmobile for traveller/tourist.
http://www.bmobile.ne.jp/payg_sim/travelers_to_japan.html

if your friend can get bmobile from BIC Camera or Amazon, he can buy local/resident version of data prepaid SIM 30days.
http://www.bmobile.ne.jp/product_data.html


eConnect - leasing NTT Docomo line
7/15/ 30 days .. 100MB perday/1GB/3GB/5GB
no need to return SIM.
https://www.econnectjapan.com/products/sim/


So-net
http://www.so-net.ne.jp/prepaid/en/


IIjmio
https://t.iijmio.jp/en/

simply buy an internet sim and then use skype to make the voice calls. it is the easiest solution

I already concluded that i will make calls through WhatsApp, LINE, SKYPE or VOIP. But 'simply buy an internet sim card' is really not simple in Japan. Confusing and conflicting information, good and bad providers etc.
The most recent suggestion a tourist friend gave me: go for a pocket WIFI, a fast one is more expensive than 2 sims but you can use up to the 4 devices that we together have. Good coverage promised.
Any advice on that?
Any recommended provider or plan?

simply buy here: https://www.japan-rail-pass.com

All the tourist SIMs are basically the same, they only differ in the data allowance or period of usage, and of course on price. None is inherently better than others, it's about which one best suits your usage.

Thanks for the suggestion, but thanks to a local Japan friend I already found a much cheaper option: Sakura
https://www.sakuramobile.jp/pay-as-you-go-wifi/?gclid=CjwKEAjwxce4BRDE...

Thanks for all assistants!
Problem solved.

But 'simply buy an internet sim card' is really not simple in Japan. Confusing and conflicting information, good and bad providers etc.

Japan is probably one of the easier places to buy a data sim because everyone is basically reselling the same services. That means the coverage doesn't really vary and you can buy solely on price.

The most recent suggestion a tourist friend gave me: go for a pocket WIFI, a fast one is more expensive than 2 sims but you can use up to the 4 devices that we together have. Good coverage promised.
Any advice on that?
Any recommended provider or plan?

Great idea if you have multiple devices, but not so much if you ever plan to split up. Coverage will be the same as a prepaid sim. Pretty much all of the carriers are the same so buy whichever has a plan that suits your needs.

Thanks for the suggestion, but thanks to a local Japan friend I already found a much cheaper option: Sakura

Be sure to read the fine print as Sakura Mobile charges a daily rental fee (50 yen/day) on their prepaid data sims, which is a fairly uncommon practice. They also have a shipping fee, which many providers waive. For a 21 day, 3gb plan you'll actually pay less by going with other providers, Econnect for example, which could save you a few hundred yen. Or if you'll use less than 100mb per day (which is a very reasonable limit for the average traveler), then look for a limited daily plan to save even more money.

Btw, voice sims are not at all difficult to get. But they are either cheap and limited to voice, or expensive (but include unlimited data), making them not so popular for tourists.