Mio Mizuno, a high school girl who wears only plain underwear, was changing one day, when her classmate Keita Urashima accidentally comes into the room. Mio was shocked when Keita asked her, "Is that the kind of underwear you like wearing!?" Mio runs away, thinking that he must be a pervert of some kind. However, it turns out that Keita is actually the designer for a lingerie brand that Mio admires very much! According to Keita, there are many other girls like Mio who have troubles with their underwear… (Source: MF Bunko, translated)