Banana wa Oyatsu ni Irimasen

From Kiwimyweewee:

One day, I suddenly became a ‘big brother’ and everyday I am called out of my bed by a sweet and tender voice. The person who’s been preparing my bentos and making me snacks is my adorable…little brother. That’s right, he’s much cuter than a real girl and he’s actually my little brother!
Despite of this grim fact, I still can’t deny myself from falling for him…
Living together seems like the ideal situation for love games, but it seems like I will have to put a stop to this?!