Ordering instructions are available via the page listed above, along with many more original drawings still available on his site. I actually got a second original by Kago this past week, so my art coffer is all tapped out :)
I emailed with Kago again this week, and he let me know that you can buy copies of a few of his manga directly from him as well. The following titles are available (+ shipping). Simply send a list of what you want to his email and he'll give you an estimate of cost. I've found he gets stuff in the mail within a day or two once you Paypal the money.

アリ地獄vsバラバラ少女 - Arizigoku vs Barabarasyoujo 1,260JPY

おばあちゃんが死体くさいよ - Obaachan ga shitai kusaiyo 1,260JPY

飛び出す妄想 - Tobidasu Mousou 1,565JPY
Happy holidays! I'm heading to the Midwest to visit family starting tomorrow. Will try to write a few posts on the plane(s) and get them up before Christmas. Hope all of you guys are doing really well and have relaxing breaks ahead of you!