"The Door to Heaven"
When to do this: Anytime!
Talk to the bartender behind the counter at the Inn regularly. Talk to him twice each visit and soon enough you and him will become friends. The he will give you "The Door To Heaven". It's a rare wine made by Karen's grandma a long time ago that your grandpa asked the bartender to keep. Then you can...

...Save the Vineyard
When to do this: The second year before Fall with Karen's heart yellow.
Talk to the Harvest Spites after getting the old wine and they'll talk of nothing else and tell you to go make an offering in the Goddess pond and make a wish (wake the fairies). The Goddess will take you to the sleeping grapevine and waken it and the tree will ask the Keifu fairies to return. In Autumn the Goddess will come to you in a dream and tell you the harvest will be good again. And the vineyard is saved. The following day Karen will come to get you to see the dance of the Keifu fairies and your photo will be taken.

How to get the Red Vase
When to do this: When you have a blue stone
Give Saibara(The mean old man at the sovenior shop) a blue stone from the mines The next day visit him again and he'll say that he refired the red vase (that he previously said was a mistake) and you can buy it.

The Blue Mist Seed
When to do this: late Spring or ealy Summer
This will appear in the Florist Shop in late Spring or early Summer when Popuri's heart is at least yellow. Buy this on a day when there are no festivals coming up in the next week so you don't miss a day watering it and have to start all over and spend another 500G for it (if you mess up, it will be for sale again at the Florist Shop). You can plant it every summer but you only get a photo for the album the first time around and not additional times.

No feed but still eggs?!?!
When to do this: When you have the stairs.
Take your Chicken up on the roof and leave it there. You won't have to feed it and it will still have eggs.