Kill Me Baby is a four-panel manga by Kaduho, serialized in Manga Time Kirara Carat since July 2008 and adapted into an anime series from January to late March 2012. The series is about an ordinary high school student named Yasuna Oribe, whose two best friends are an assassin named Sonya and a ninja named Agiri.
Volume 2, Chapter 18
Culture, Juggling and Cavalry Battle (S01E07)
Yasuna drinks water from every source she can find, only becoming bloated when she drinks from a hose.