A consequence for every action.

An anime about time travelling and romance. The latter part is very similar to works by Key where the series starts with comedy and ends in tragedy -- a very successful formula, I always fell for it. This series executes this formula exceedingly well, referencing much of otaku culture in its comic moments, and ends with life and death decisions that changed the world. Just this bit alone would have made the series very much worth watching. Plus the series does not really end in tragedy :)

On the first part, the time travelling bits: anyone with any eroge experience will recognize and resonate with the save-resume-retry loop, which is also done very well in this anime. But nevermind such similarities, once you accept the possibility of sending a small amount of information to the past, the science fiction part of this series becomes very plausible, the rest of the series becomes very plausible, more so than many other science fictions that used this plot device. It is very carefully done, and just about every event and object is accounted for, not a moment wasted. This part is what makes this series worth watching again.

+ Google