This is a sequel to "Amaoto ni Majiru" and "Amaoto ga Tsumugu", but I think you can read it without having read those... But, just to be sure, a summary of the last part! Since Reimu's pot had holes in it, they went to the shop Marisa suggested to buy a new one, but as it turns out, it was Marisa's old home, the Kirisame Second-Hand Shop! Reimu wondered why Marisa would take her there after having run away, but then realized she just wanted to see her family. Once they got their pot and were just about to head back, rain started pouring down, and Marisa's mom lent them one single umbrella. That's the gist of it.

Marisa Rainy days remind her of home and make her cry.

Reimu Worries about Marisa.