The story centers around Kouta Hasegawa, a high school student who is an ardent fan of the yellow Pom Pom Purin dog. By chance, he ends up going to the same school as Yuu Mizuno, who shares Kouta's love for Sanrio's adorable characters, particularly the bunny My Melody. Yuu reassures Kouta that there is nothing wrong with being passionate about these characters, and together with their friends Shunsuke Yoshino, Ryou Nishimiya, and Seiichiro Minamoto, they learn to embrace their fondness for the characters and shed their embarrassment.