Uke's (?) father is a photographer who's known world wide. Just after getting remarried, the father leaves the country for work, leaving uke with step family. To get along with his new family, he hides his feelings and puts on a good boy face, but soon it becomes too much and he runs away. He's found by his new Lil bro, seme (?), and brought back home. Since then he's been in lobe with him. The brothers grow up doting on each other, but uke still hides his feelings. One day, seme sees uke out with some other guy and realizes that he loves uke. There's some ups and downs involving uke's father and their elder sister, but eventually things settle and they get together. Happy ending. Kinda tropey for step siblings, but an OK read.
Kimi wa Boku no Uso