Three brothers with different mothers but the same wealthy father find out that there might be a fourth brother by a fourth woman. The three brothers' father order them to look for the last brother (actually supposedly the eldest one), but that's really important because a DNA test reveals that the "new brother" isn't their father's biological son.

What's important is that the eldest of the three brothers falls in love with the "new brother" who's thankfully not his brother. The story isn't as confusing as it may sound here, and that's a good thing. But there isn't really much of a story because what is really meant to be shown is each brother's BL romance, except that the romantic relationships aren't that fully developed either.

Despite the flaws, the BL aspects are rather cute. Strangely enough, although Brother 2 and 3 (the younger ones of the three brothers) behave as though they have boyfriends from the start, it is later revealed that their boyfriends are actually their best friends, and it is only towards the end of the series that they and their boyfriends confess their love for each other. Nevertheless, their interactions are sweet, and it's hard to dislike the show too much.