The plot is a mixture of strange sci-fi happenings intertwined with a pretty sweet romance although the main couple both have slightly twisted personalities. The characters each have their interesting quirks and backstories with enough time given to develop them without turning the show into a harem. You do end up caring for them and what they go through and the show strikes the right balance between happiness and overcoming torment without going into extreme depression or messed up feelings as some other shows do.
The visuals, music and voice acting are all top-notch and the show does some interesting things with the ending segment and characters. The author of the original work previously made Sakura-sou No Kano Jo which despite its ecchi side was an emotional roller coaster. He doesn't disappoint with this very different yet bright and emotional story with understated sci-fi elements.
This is a great show and I highly recommend it.
