Mahou Shoujo Elena

With the help from a mysterious creature, Elena turned herself into a magical girl to beat Zoid, a tentacle monster to save her sister, Emile.<br><br> Since that day, to protect her sister and to keep peace on the earth, Elena started to fight against the ugly creatures as a magical girl!<br> However, what awaited her is a harsh destiny: immoral days of naughty humiliations. And her battle eventually involves her sister and her dead mother.<br><br> Can Elena exterminate the tentacle monster, or is she driven crazy and lost her reason by the ecstasy?<br><br> (Source: DLsite)