Kuchizuke Wa Niji No Ue De

From September Scanlations:
Momozu is a frumpy, indoorsy ‘hare-otoko‘, and sunny weather seems to follow him around, while Toyotama is a cheerful, athletic ‘ame-otoko‘ who’s constantly dogged by stormy weather. When the two meet and Toyotama convinces Momozu they should join a mountain-climbing club together, it’s a total case of opposites attracting!
NOTE: September Scanlations has scanlated the main story but will not be translating the rest: “while this is part of an anthology of shorts, we won’t be translating the others, as the quality was not quite up to par and we don’t scanlate single-chapter one-shots regardless”