As someone who loves sci-fi and shoujo, I would have never expected any sort of crossover between Moto Hagio and Ray Bradbury, it's so awesome that there are manga adaptations of his work! I'm so glad this was scanlated to completion, especially because I'm betting the chances of this getting officially licensed is incredibly low.
If anyone wants to read the original short stories in one collection (like, say, on an e-reader), you can find all the stories that were adapted (except for "R is for Rocket") in the collection "The Stories of Ray Bradbury". You can find "R is for Rocket" in a few collections-- if you're looking for an official e-book release, you can find it in "Bradbury Stories: 100 of His Most Celebrated Tales".