Yuriko wears the Zashono Elementary School outfit, with a pink sweater instead of a vest and purple skirt with red shoes.
She is almost the exact opposite to her sister for two reasons. One is that unlike her sister, mother, and for some reason her brother, her chest is not very developed with only an A-cup through the series to compare to her sister's original F-cups which grow through the series. Something she is very jealous of.
The other difference is that unlike her sister she not only openly confesses that she likes Densuke and constantly makes amorous advances towards him. Often jumping him in such a way that it deliberately presses her crotch against his face as well where she moves his hands to her breasts and holds his wrist in place so he can't pull away. In one instance, Yuriko and Chiharu's breasts are temporarily switched by one of Kyoko's experiments gone wrong and while Yuriko is in possession of her sister's breasts, she keeps Densuke captive in her room and forces him to play with her breasts for hours until the procedure in reversed.