I'm fairly positive that "Jiro Irima" is an unconfirmed reading that's been around on all of the VGM sites for forever and a half. I haven't found an actual reading for the name anywhere, but I think it might be correct, though.
His real name is Hideo Irimajiri, and he works (or worked) for Mainichi Broadcasting System (MBS). He gave a talk/presentation/whatever at the A&V Festa 2008 event. There's a biographical paragraph about him on the event's online program:
http://www.avfesta.com/avf08/event/seminar.html. The paragraph mentions in the last two sentences that he used (or uses) the name 入間 次朗 for sound work, and it specifically mentions the Record of Lodoss War game. "Irimajiri," "Irima Jiro," etc.
What, you want more? UGH alright hold on. Here's a transcript of a panel he participated in about what looks like surround mixing:
http://surround-terakoya.jp/terakoya...6TERAKOYA.html. About 3/5 of the way down or so, Irimajiri talks about the production of the album "Bach Beat" by the marimbist Makoto Nakura. I don't know if he himself was responsible, but he talks about the engineering and all that pretty extensively. And here's a completely random page on the internet that says surround mixing for that album was done by "Jiro Irima":
http://surround2011.blogspot.com/200...to-nakura.html.