What's the source on the reading of this name as "Izumi Arisa"? I've never seen anything solid enough to go on, so I'm checking up.
I've seen "Izumi Arisato" around, mostly in reference to some w-inds songs she wrote, but not on any sites I'd consider reliable. A few Japanese venders (
Amazon.co.jp,
CDJapan) go with that too.