I don't need a girlfriend, but I want to have lovey-dovey sex. I want to go on a romantic date, but I don't want to be tied down. It is difficult to find such a convenient relationship. Natsuki is older than me and calls me as soon as she finishes work. We contact each other almost every day, tell each other that we like each other, and have sex live, but we haven't explicitly talked about dating. Is this a sex friend? she?