Based on the same Manga.But the story follows only the basic outline of the manga and all the other things are messed up like character development, emotions ect.In my view if you love the Japanese drama then you are going to hate this film.
Based on the same Manga.First adoption of the Manga,, but the ending differs from the Manga as the Manga was on going at that time.
Similar concept, divorced couple get back again.If you like one of them then sure you will like the other.