Had a team meeting here when I worked for a food tour company, and it was recommended by one of the other guides on our team. As the name suggests, it specializes in all things green tea. A pleasant surprise for me was seeing that they had cha soba (green tea soba), which while normal overseas is not as common in Japan itself.
If you consider yourself a matcha-lover or matcha connoisseur, you may be happy to know that their green tea drinks list is extensive, with more than enough choices to satisfy anyone. Green tea is present in some form or another in each dish/dessert, and in typical Japanese fashion, the plating and visual presentation of each dish is stunning as well.
I would definitely recommend Omatcha Salon for any green tea lovers, or even just to have a very traditional-modern Japanese experience meal while in Osaka.