^ Think those exact gifs might be from the 2nd vid linked here, these were a series of Visual Web Young Sunday videos (which had accompanying photoshoots) from a year or two ago:
My favourite was always the one where Mayu and Yuko were hugging - and Mayu looked a bit scared of Yuko.... however, after quickly flicking through these four, I can't find that bit - only Mayu hugging Yui (in week 2) and Mayu hugging Yukirin (in week 4)... so maybe the Mayu-Yuko hugging vid was a different series, as these ones are marked Volume 489.