Kagaku Chop
Sai Suzuzono, chief of the Science Club, spends all of her time developing crazy experiments to satisfy her curiosity, like a real "mad scientist." The only one trying to contain her antics is Ren Nagakura, the class committee chairman; but Ren, despite being the class chairman, is also little clueless about other people (i.e. she's an idiot). And with Ren's involvement, Sai's weird experiments always turn out even weirder...
Note: Includes 5 extra chapters.