Tsugou no Ii Jiraikei Kanojo to Karada Dake no Kankei o

Lyon is a beautiful landmine-type girl I met on a net game, who was playing in her underwear, even though we had never met before. From then on, whenever I wanted to play games, go out, or just have a late-night ramen craving, I could call on her to hang out with me. But neither of us knows each other's real name. We are not even really friends. I am comfortable with such a convenient relationship. Because besides Lyon, I have a cousin and a junior colleague who are also landmine-girls. "Oh, if you were actually my brother, then I could safely pamper you without getting the wrong idea." "I can be another girl for you. I don't care if I'm second or third in line." They want to have a convenient relationship with me, too... (Source: Fantasia Bunko, translated)