The manga is funniest at the beginning. a downer is the addition of divine events that take place outside of the original scope.
The MC is thrust around by a rather high paced and demanding environment where his original self has been forced to "disappear" while his girl-self takes over his position in life (for now)

there is a fun plotline to follow but its still possible for the whole premise to become a washed up failure depending on just how good the author is (I don't really know this myself :S)