Note that this is in downtown Osaka, NOT the Toyonaka/Suita campus of The University of Osaka.
There are many good business hotels near the Osaka-Umeda station (~20 min walk from the workshop venue) and around the workshop venue. But late March to early April is a popular tourist season for cherry blossoms, so you should try to book the hotel soon.
Restaurant and Cafe
You can find some good restaurant and cafe nearby. Here's another link to GOOGLE MY MAPs.