Customs at Haneda before another flight - is 3 hours enough time?

Due to a multi-city itinerary, we have a non-connecting flight at Haneda. From my understanding, we will need to get through customs/immigration and collect our luggage before checking in for our next flight. We're due to arrive at 1:45pm and the departing flight is at 4:50pm. Is 3 hours enough time? All the flights are out of terminal 3. We'll fill out forms online, but any other tips/guidance/reassurance would be appreciated.