Ore no Otouto no Honjitsu no Onedari

From Renta!:

"I want to sleep with you, Chihiro." When my little brother said that, I, Chihiro Ichinose, had my whole life turned upside down. Chikage and me are brothers and we get along great. He's a manga artist that I'm proud of and it's already been a few years since I came with him to Tokyo. Is this my punishment for getting too used to living in comfort!? His sudden declaration of wanting to "sleep with me" made me very confused, but he won't stop being persistent. No matter how much material he needs for his yaoi stories, this is too far! But, when my cute brother begs me in desperation, I can't refuse… I think… What should I do!?