JDrama Movie Hunt

So i'm looking for this particular J-Drama movie that i've watched around 2 or 3 years ago.
The clues that i have are as follows.

1. Father and son now live together after the wife died after giving birth to the said child
2. It involves the rainy season.
3. They lived in a rural area.
4. The child is studying in between kinder and grade school.
5. Mother suddenly shows up without any recollection as to who she is.
6. Her time was limited by the change of season.
7. near the climax, The mother bought / ordered cakes that will just be picked up by her son every year during his birthday and the maximum was on his 18th birthday. (not sure about the max date).
8. It involves teru teru bozu

That's all the clues that i ahve... Can anyone help me on this one.