Nikkei reports on the matter
This was also rumoured back in September already here but I reckon we're nearing an official announcement in the days ahead, so there is a rerun via local media.
For some context, the exchange currently operates from 9am to 1130am local time before pausing for an hour break and then resuming at 1230pm to 3pm local time (5 hours in total) so an extension is likely to be applied to the closing time.