Kouta Hasegawa, an ordinary high school student, treasures his Pompompurin plush gifted by his grandmother. Bullied for his fondness of Sanrio characters, Kouta hides his love. Serendipity strikes as he crosses paths with fellow Sanrio enthusiasts at school: Yuu Mizuno, a charismatic heartthrob; Shunsuke Yoshino, a soccer team member; Ryou Nishimiya, a helpful underclassman; and Seiichirou Minamoto, the esteemed student council head. Embracing his passion with newfound friends, Kouta sheds his shame and embarks on a journey to showcase their shared love through a vibrant cultural festival play, illuminating his mundane school days with a touch of magic.