Kitto Kiss O Suru Toki
A sweet and rather dense young man realizes he's in love with his best friend thanks to the help of his younger brother.
Ichiban Chikaku De Koi O Suru
This opens with a story of an adopted brother in love with his older brother. It ends with the low-key Free AU, complete with Haru/Rin ending fanart! Yay.
Gokudou Darling
I was about to drop this, but the chapter I was on turned out to be the last. It's not bad, just didn't really grab me. A proud man who has lost his mother refuses to accept money from his wealthy step family, who turn out to be yakuza. His step brother is into him; his other step brother assaults him. It missed a mark somewhere for me.
Abarenbou Kareshi