Umaru Doma is a model student who has a hidden side: when she gets home each day, she puts on her hamster hoodie and turns into a sluggish otaku fond of junk food. As Umaru continues these daily antics, the friendship between her and her classmates—Nana Ebina, Kirie Motoba, and Sylphinford Tachibana—deepens, and more and more interesting events begin to unfold. Of course, these events give rise to numerous questions. What did Nana ask of Umaru's brother Taihei? Who is the mysterious girl with the diamond hairpin? And most important of all: why does this girl seem to know Umaru? These questions and more will be answered in Himouto! Umaru-chan R!

For more than four hundred years, the Takamimi Shrine has stood in Tokyo, enshrining the local goddess: Elda, a magical elf summoned from another world. The immortal elf has been served for 15 generations by the family who summoned her in the Edo period. Now, after Koito Koganei turns 16 years old, this responsibility falls onto her. Serving as Elda's shrine maiden, Koito must balance her responsibilities with her daily school life. This proves to be difficult because Elda is a total social recluse who loves video games, collecting toys, and eating snacks. In an effort to get the lazy shut-in to experience more of the outside world, Koito juggles her time between indulging Elda's various hobbies and getting her to interact with the rest of humanity. Along the way, Koito learns more about the history of the area and what makes the goddess so loved and spoiled by the locals.

While walking through the forest one day, a witch named Alyssa finds a bush glowing with a magical aura. She discovers a baby who, although not a witch, possesses magic that is too strong for that of a mere human. As such, Alyssa decides to raise the child as her own, naming her Viola. Sixteen years later, Viola is all grown up and now towers over her youthful mother, and her mature looks cause many to confuse their ages. Nevertheless, Alyssa adores her child despite Viola's possessive streak and tendency to drive away anyone she fears will take away her mother's love. Viola may not be sure where she came from, though she has all she needs in Alyssa and the plethora of Alyssa's friends who have come together to raise her. Under Alyssa's guidance, Viola will learn to master her magic and make her adoptive mother proud.

Based on the one-shot manga .