BTW, I'm playing two Zelda games: OoT MQ 3D and Majora's Mask on Wii VC, but for now focused on MM.
So far I have 14 hearts and almost ready to go to the Great Bay Temple. Before I do, I need to get 2 pieces of heart hearing Anju's grandmother stories, already get the All-Night Mask.
I already now where are the rest of the items, masks and hearts left to completition:
1 heart container in Great Bay Temple, another 1 in Stone Tower Temple and the final 1 formed by 4 pieces in the moon. Then, 3 pieces after Great Bay completition: fisherman platform game outside Pirate's Fortress, and 2 more on Snowhead after defeating Goth, one in a chest underwater and the other one with the frogs. That's 18 hearts and 1 piece. So 7 pieces left.
There are 2 in Clock Town left. First one with Mayor Dotour after getting the Couple Mask, and the other one in the Bank. The rest are in Ikana region, only one in the graveyard and the 4 left in the valley. The four are: the Deku mission in every region tradind title deeds, Ikana Castle pillars, Poe's battle game and finally the cave with the 5 middle/bosses enemy battles. And with that, 20 hearts.
The boomber's notebook have also some people left to be happy, Anju's grandmother stories, Anju and Kafei after getting the Sun Mask from Sakon in Ikana, Mayor Dotour after ending disscussion in his office using the Couple Mask and the invisible soldier in the road to Ikana Valley.
From the Item screen, only one bottle left which I'll obtain in the Ikana graveyard with the help of Dampe, the Fairy Sword from the Great Fairy in Ikana after getting the 15 stray fairies from Stone Tower Temple and the Ice/Light Arrows from Great Bay and Stone Tower Temples. Goth and Twinmolds masks and defense upgrade from the Great Fairy at Great Bay.
Finally, the 6 masks left to complete the screen are: Stone Mask (road to Ikana), Couple Mask (Anju and Kafei), Gibdo Mask (Ikana Musicbox house), Captain's Mask (Ikana graveyard), Giant Mask (Stone Tower Temple) and Fiercy Diety Mask (inside the moon).
Still some time left I guess.