If you have some Aeroplan points, you can do 60k YHZ-FRA-HND on Jul 1 in economy, or 87.5k in Business class, arriving in Tokyo on Jul 2 10am.
If this is one way, pay attention to how much the return flights would cost. Finding a reasonable hotel in Tokyo to stay beyond the original plan, which probably involved a special price for a block of rooms during the conference, could be very expensive too.