ウェブWebsite. irisohyama.co.jp/english/. Iris Ohyama head office. Iris Ohyama Inc. (アイリスオーヤマ株式会社, Airisu-Ōyama Kabushiki-gaisha) is a Japanese consumer plastic manufacturer based in Aoba-ku, Sendai, Miyagi Prefecture. [1] [2] It is the leading storage organization manufacturer in Japan.