Mai Nanase is a high school girl who can't keep up with her classmates when it comes to gossip and love affairs. Normally, Mai isn't one to fall in love...but when she overhears a conversation between her brother and her brother's friend, Souta, she finds herself unable to think of anything else. What did he mean by "...your sister is cute...?" Could Mai have feelings for someone? This is the start of an exciting adventure for two people who are too naive for their own good!