Choujigen Game Neptune The Animation: Yakusoku no Eien - True End

A mysterious illness known as Bad End Syndrome strikes Nepgear, Uni, Rom, and Ram, trapping the younger Candidates in feverish nightmares. The only known cure is the Shimmering Flower, so Neptune and Vert cross into another dimension where familiar faces exist in unfamiliar forms and the flowers are said to bloom atop an enormous tower.

The rescue becomes a race against time. Unable to rely on their usual transformations, Neptune, Vert, and their new allies must climb thousands of floors before the passage home closes. Reaching the cure is difficult enough, but when one companion is left in danger near the summit, Neptune must choose between returning on time and refusing to abandon a friend.