ITT: discuss lolis that are totally badass.
Umi takes the cake. She literally bashed onii-chan over the head, dragged him off, and chained him to a bed just to have him all to herself and keep him away from big titty onee-chans. Then, when his enemies came to kill him, she went guns blazing and smoked most of them, only to die shielding onii-chan from a bullet in the end.