Kaori's diary strips away the sweetness of the main series and shows you what it costs to forget the person you love every seven days. These aren't story episodes, they're her unfiltered thoughts, the weight she carries alone, the small mercies of rereading her own words. If you watched the original and felt something real, this is what happens in the spaces between.
One Week Friends Kaori no Nikki is a set of twelve slice of life specials from 2014. They were not broadcast on their own: they came as bonus content packaged with the Blu-ray and DVD editions of the series.