Majora's Mask: Anju and Kafei|
Head to the Mayor's residence in East Clock Town, next to where the Bombers' hideout is at 10 AM. Enter the door on the right, and speak to the chubby woman with the red hair. She is Kafei's mother and will give you Kafei's Mask.
2:00 PM - 2:15 PM
Go to the Stock Pot Inn and talk to Anju when she's speaking to the postamn to hear their conversation. After he leaves, talk to Anju, say Yes and she'll give you a room key. Now put Kafei's Mask on and she'll ask you to meet in the kitchen at 11:30 PM.
Go to the Inn on the right side of town, and on the first floor, make your way around the stairs to the last door on the right side until Anju comes in and stops walking. Talk to her to get a letter to mail to Kafei.
12:00 AM - 6:00 AM
Go outside and find a mailbox. Equip the letter to a C-Button and press that button to mail the letter.
Go to Kafei's house at the Laundry Pool and wait for the postman to come and deliver Kafei's mail. While Kafei is getting it, go inside his house and wait for him to return. Talk to him and he will show his true face and give you the Pendant of Memories to deliver to Anju.
4:00 PM - 8:30 PM
Go back to the Inn and deliver the Pendant to Anju. Now warp to the Final Day.
Note: The following step should only be done once. Complete A and B, and go back in time, repeat everything up to here and head straight for the step after this.
1:00 PM - 6:00 PM
Make your way back to Kafei's House, and go inside to find the Curiosity Shop owner inside. Talk to him to get the Keaton Mask as well as the Express Mail. You can deliver it in two different ways:
A) At 6:00 PM on the final day, go to the Milk Bar in East Clock Town and talk to Madame Aroma when wearing the Mask of Kafei, then give her the Express Mail to get a bottle with Chateau Romani (you must have the Romani Mask to do this).
B) On the final day, take the Express Mail over to the Postman's house at 6:00 PM. Give him the Express Mail, and he will go deliver it to Madame Aroma in the Milk Bar for you. Once he delivers it and goes back outside, wait for him to stop. He'll say that he's finally fleeing, and he gives you his Postman's Hat.
Any time before 4 PM
Head to Ikana Canyon and go right from the Octoroks. Head all the way to the two stones, behind which is Kafei. Now wait until 7 PM (warp if you must), and Sakon will show up and open the stone door. Follow Kafei inside.
Inside, you must solve a timed switch puzzle to recover the Sun's Mask. You control both Kafei and Link in here. Here's the trick: the blue switches open doors, the red switches speed up the recliner belt, and the yellow ones slow it down. Here's the order for room 2:
Once Kafei has the Sun Mask, soar to Clock Town and enter the first door at the top of the stairs of the inn where Anju is waiting. With 1:30:00 remaining, Kafei will enter. As Tatl points out, they seem to resemble a mother and child. They will exchange Sun and Moon masks, and will give you the Couple's Mask for being their witness to exchanging vows. They tell you to take refuge. They will face the morning...together.