Japan prepaid data sims are just that, data. If you want calling you'll either need to use VOIP on a data sim like Google Voice, LineOut, or Skype, Bic Travel Sim w/ Brastel VOIP; roaming sim from US/HK/Thailand/China; or rent/buy a sim from Mobal, Softbank, GAC, JCR. There's very few ways around the residency requirement for JP carrier (non-roaming) voice service and most take some time (plus mailing address) to validate.
Cost, reliability, ease would be T-Mobile US free roaming, followed by Google Fi (better speed, pay $10 per GB). I've read Sprint roaming on Softbank is also good but I wouldn't change carriers for this. These can all be setup in the US. Inside Japan, all the JP MVNO prepaid data sims will be subject to throttling and data caps.
Docomo still offers their Travel Sim until Sept, but are cutting off the application deadline and there's no calling.
Roaming SIM like Thai AIS is also a good choice with details upthread. AIS requires a third party website or Thai CC to top up and while I think using AIS is straightforward, I lent a friend my AIS sims and he was a bit stumped on how to load/check-balance (despite e-mailing clear instructions). AIS also roams in other countries.
AIS
https://www.ais.co.th/roaming/sim2fly/en/
Rental Sim options:
Mobal
https://www.mobal.com/japan-sim-card/
Softbank
https://www.softbank-rental.jp/en/re...n/sim_card.php
GAC
https://www.globaladvancedcomm.com/simrent.html
JCR
https://jcrcorp.com/japan_mobile/jap..._rental_4g_3g/
$10 per GB is reasonable for Japan. AIS, 3HK per GB roaming is less than that. Most prepaid JP MVNO a bit more.