KissXSis (2010) : 1x3

Keita gets annoyed with being kissed by Ako and Riko him all the time and instigates a ban on kissing. Overhearing that Keita likes sweet things, Riko tries to make him some chocolate, but can only manage something horrific. After finding one of her father's dirty DVDs, she gives Keita some chocolate lipstick, persuading him to eat it off her lips. Before they manage to go any further, they are interrupted by Ako who destroys the lipstick. Riko gives Keita another chocolate lipstick, however it was made from the horrible tasting chocolate that she had made.