I'm a big time-travel fan - (and also a big Japanese pop culture fan) this is a slightly different twist on the theme - so I was already sold. The main character and the recurring supporting characters are all quirky and charming. I think it's fair to say that this is a very Japanese show - but easily accessible to anyone in the world who's willing to read subtitles. Not sure if dubbed soundtrack is available - but even if it is, listen in Japanese, read the subtitles!
The humor is subtle and dry, and the writers and Yutaka Takenouchi, who plays the taxi driver, slowly reveal a charming, imperfect, and funny protagonist.
The reason I say it's so accessible: first, the dialog, scenarios and characters are mostly ordinary people-who just happen to be Japanese. The theme touches on something most human beings everywhere can relate to: the wish to go back and re-do a bad choice-big or small - that may have changed their lives.