Isayama Natsu follows his own rhythm, discarding socks, releasing butterflies from rooftops, and having sexual encounters with other male students in the school's tool shed. Taneda Kouki, who sees himself as ordinary in every way, inadvertently comes across Isayama's secret meeting while taking a shortcut. Isayama's eccentric conduct bewilders and intrigues Taneda, prompting him to reevaluate his understanding of what is normal.