The swimsuit ones are from the OVA, the last ones I have no bloody clue... checking the site now
EDIT: Apparently I was wrong... it should be a preview of some sort for the upcoming spring season with part A tomonori/eucliwood weird swimwear, and part B about yuu's surprise birthday party... but that's with a grain of salt, I am quite drunk now, which impairs my foreign language comprehension, so wait for a more credible speaker... 'night