Iroe Genma is a third-year high school student who is often called "Elder Sister" despite her short stature. This troublemaking teenager serves as the president of her school's Model Club, which focuses on constructing plastic models of various objects and structures, including cars, boats, and even robots. Accompanied by her two underclassmen, the violent Hazuki "Okappa" Okamoto and the rational Makina "Makimaki" Sakamaki, the small group attempts to fulfill their club duties but is frequently sidetracked by a myriad of distractions. From battles between club members to lessons on how to confess to your crush, these three schoolgirls find themselves caught up in all sorts of wacky and downright outrageous situations!