I wanted to put this here to provide some information for anyone who wants to purchase the plays. And yes, I'm also trying to promote the plays :)

Here are the links to the main shop for each play. The fourth play will be released in March this year but you can pre-order the DVD/blu-ray now.

Yonakidori Blues: DVD

Ruritsubame Blues: DVD | DVD special edition (includes the 25th anniversary celebration of Mirage with sensei and cast)

Yashashuu Boogie Woogie: DVD

Gurenzaka Blues: DVD | Blu-ray

The main shop doesn't ship outside Japan so you may need to use a proxy service to acquire the DVDs/blu-ray.

Some recommendations:

CDJapan - Proxy shopping service that ships worldwide. Most of the plays are already listed on their site except for the Gurenzaka Blues blu-ray (you can submit a new request for it if you intend to buy the blu-ray)

Yonakidori Blues: DVD

Ruritsubame Blues: DVD | DVD special edition

Yashashuu Boogie Woogie: DVD

Gurenzaka Blues: DVD

FromJapan - Proxy shipping service that ships worldwide. I've been using this to purchase some of Tomita's other plays that are not covered by CDJapan's proxy service and have not encountered any problems so far. To make use of this service, you have to input the website link of the item that you wish to purchase, wait for a quotation, make the first payment for the item, wait for the item to arrive at FJ's warehouse, then make a second payment (shipping cost & service charges) to ship the item.

In my opinion, the plays are a better adaptation of its source material than the MoB anime. So do support the production if you can. There are also other play-related memorabilia for sale such as pamphlets (program), photos, etc. Note that if you spend more than 10,000 yen on Mirage-related goods in a single purchase, you get a free photo or a tote bag. 

I've also put together a short video, for those who want some idea of what the plays are like, featuring the one performance that makes the plays well worth the money, that is, Tomita's performance as Kagetora. I've included comments (mostly sourced from tweets) from sensei and a few others on his performance, as well as clips of him from the first three plays.

http://www.mediafire.com/file/8xgazdcfseasl5d/MoBPlays_Tomita.mp4

^{(please do not post or upload this video to any other site)}