Kirai Kiraimo

From Deux:

The Konoe and Kazuki families have been fighting like cats and dogs for generations. Masaya Konoe and Yuma Kazuki attend the same elite high school and are known to all as arch rivals, but do they really hate each other? Masaya still cherishes a childhood memory of a time when Yuma shared a "treasure" with him. Now they share a secret attraction. Can they hide their passion? Burning desire has a way of erupting into flames!

The Deux published version of this manga does not include the short story called, "Water Lily". It's about two brothers where the younger brother is in a coma and the other takes care of him. The older brother molests his sleeping brother not realizing that his touches are being noticed.