3-pun Instant no Chinmoku
It is a very mature story that does involve incest (step-brothers) as the main couple. However, I find this better than other incest manga as - luckily - the two main chars do have feelings for each other, although none of them realize the other's feelings yet. Oh well. EDIT: So I just finished reading this and, I admit that I was confused a lot (but then again that must be bc it's currently almost 5 AM in the morning ORZ), and still found the shota-like OLDER uke veeery unsettling. At least there's a happy ending. ;-;
Ore No Mono Ni Narinasai.
Kyoudai-biyori
Can't really rate this since it was incest, but it was very very nice. a good read in short. ^.^
Mayonaka no Oyatsu