Himōto! Umaru-chan (干物妹!うまるちゃん) is a Japanese manga series by Sankaku Head.
The series follows Umaru Doma, a high school girl who lives with her older brother Taihei, At school Umaru appears to be the ideal student with good looks, top grades, and a lot of talent. Once she gets home, however, she reverts into a layabout who spends her time lying around, playing video games, and constantly depending on her older brother, much to Taihei's dismay.
Over the course of the series, Umaru's alternative personalities help her become friends with her female classmates Kirie Motoba, who has a reputation of glaring at people; and Sylphynford Tachibana, a competitive school rival; both of whom turn out to be little sisters of Taihei's coworkers.
The Manga first appeared in Shueisha's monthly magazine Miracle Jump in 2012 for two chapters, It began serialization in Weekly Young Jump magazine from 2013. It has been collected in six tankōbon volumes.