Introverted high-school student Ryuto is forced to confess to his crush, the most popular and beautiful girl in school, Luna. Surprisingly enough, she replies, "Then, how about we go out? I’m single right now anyhow." Then right after school, she invites Ryuto to her room...?! Despite being completely different from one another, including the amount of experience with love and types of friends they have, the two of them are about to embark on a relationship full of firsts!