In a school of making drugs of different sorts that could change in a DNA level were made, there was a Phantom thief of medicines in order to prevent illegal selling of student made drugs, whose real identity was a group of students which the leader was in love with a student who accidentally poured by a shrinking medicine which caused him to shrink from certain height and up to 30mins.
Kaitou Drugers! - Junjou Koi Dorobou