A high school boy hiding his love for Pom Pom Purin meets another boy unapologetic about My Melody, and suddenly shame stops being inevitable. The show moves quietly through small moments of acceptance, a character finally wearing their character pin in public, another admitting what they actually care about without flinching. It knows that the bravest thing some people do is stop pretending to be smaller than they are.

Kouta Hasegawa, a seventeen-year-old second-year at Hijirikawa High School, loves Pom Pom Purin, the yellow Sanrio dog. His grandmother gave him a plush of the character when he was small, but after other kids called him girly for it, he grew ashamed of that attachment. Then he meets Yuu Mizuno, a flashy boy popular with girls who adores My Melody and tells Kouta there is nothing embarrassing about liking cute characters. Through a string of unexpected events, Kouta also meets soccer player Shunsuke Yoshino, library assistant Ryou Nishimiya and student council president Seiichirou Minamoto, all Sanrio fans. Together the five boys learn to embrace what they love instead of hiding it, and they set out to stage a play for the cultural festival that could turn Kouta's ordinary school life into something sparkling.