Clash! Cooking Sisters! Episode 7

Illya ends up competing in a baking contest against Kuro, winding up at a disadvantage due to one of her teammates adding bizarre ingredients. The next day, Illya tries to learn how to be regarded by Kuro as a "big sister", with not much success. Later, though, Kuro states how she is relying on Illya to keep supplying her with mana.