Maria's big sister, a 15-year old nun who looks a bit older than her actual age. Like her sister she has extremely bad manners, demonstrable via a variety of public burping, farting and butt-scratching. Despite her largely nonchalant attitude she is concerned for and protective of Maria, and is described as having something of a sister complex.
In the anime's first season, she is seen only briefly in episode 8 and is not introduced until episode 2 of Boku wa Tomodachi ga Sukunai Next. She is 15 when officially introduced but later turns 16, as explained in season 2 episode 7.