Mayaku no Renkinjutsushi ~Misa~

Misa is a rare witch who researches black magic in the 21st century. It deals not with curses, but with body parts transformation. She helps her friend in the same girls' school to get a huge rack. From now on she helps any girl in need to eliminate her body defects. As a result school gets drowned in lust.

[From vndbreview]