Ane No Onaka O Fukuramaseru Wa Boku

from mangahelpers: this is the story of a pair of step-siblings who are now living alone together. the high-school-age older sister, kyoko, is pretty wild (and is even into pro-wrestling), while the elementary-school-age little brother is a fairly serious kid. he is often embarrassed by her teasing. the two of them pass their daily life together, every day cooking for one another.