A Manga Like This PLease.Don't put any unnecessary details...thanks?

Uhmm like this please: A girl and his brother didn't see each other for a long time.. so when she went to her brother's place and school.. she is always mistaken for her brother's girlfriend that's why she has no romance.... I want his brother to be popular ehhehe and the question is how can she find her romance or his brother's romance... either of them can be the main character.. BUT THE IMPORTANT PART IS THEY ARE MISTAKEN FOR BEING EACH OTHER'S PARTNER WHILE THEY ARE NOT BECAUSE THEY ARE SIBLINGS.. thanks! ^^