Liar x Liar

One day, after borrowing her friend’s high school uniform and taking a walk around town on a whim, Minato runs into her younger stepbrother, Toru! Toru believes Minato when she insists she’s someone else … but now it looks like he’s fallen in love with her high school girl disguise?! A weird, weird love story begins!
(Source: Kodansha USA)
Note: Nominated for the 39th Annual Kodansha Manga Awards in 2015.