When I try to view the column or campaign pages on my smartphone, the chat system pops up and I can’t close it.

Maezawa here. You should be able to close the chat system—or, more precisely, minimize it. I checked on an iPhone just now in case there was a bug, and tapping the × in the lower-right corner minimized it. Also, the chat shouldn’t open on the column pages. I checked those as well, and the chat system did not open there either. The behavior may differ depending on your smartphone model, so could you please contact the branch where you’re registered and let them know your phone model, OS version, and the specific pages where you’re unable to close the chat?