Renee,
Just go disneyland, forget about going disneysea, not as fun and nothing, for disneyland, DO NOT miss the night electrical parade and after the parade, the fireworks, that are the best of disneyland. If you can, stay near the disneyland for one nite. when I bring family or friend to disneyland, I usually after pick them from airport, go to disneyland nearby hotel, stay there cos it is near the airport, from there, go to tokyo, then yamanashi last before going back to singapore so that the momo and fruit you pluck can bring back to singapore instead of leaving it for too many days in tokyo before you bring back, furthermore momo very fragile, can be bruise easily, handcarry up the plane, do not check in and ask the stewardess to store it in the fridge nicely for you. or go tokyo first, yamanashi and then disneyland just before you come back to singapore. When you are in yamanashi, you can also stay a night there in their onsen ryokan, so you can enjoy the onsen in the ryokan too.most of the ryokan comes with onsen anyway. You go during summer so alot of fireworks everywhere, reach hotel, pls check with hotel staff on the schedule of fireworks (hanabi) near the place you stay, be it tokyo, yamanashi or disneyland (chiba), every area got own fireworks display.
