The punchlines come so fast you'll miss half of them on the first watch, and that's the entire point. Plastic Nee-san doesn't build toward anything because it doesn't need to, it's pure comedic friction between four girls who shouldn't work together but do. The humor lands hardest if you're the type who rewatches the same three-minute episode twice just to catch what you missed the first time.
Iroe Genma is a third-year high school student whom everyone calls "Elder Sister" even though she is short. She loves building plastic models and heads her school's Model Club, where members put together kits of cars, boats and robots. Her two underclassmen are the level-headed Makina "Makimaki" Sakamaki and Hazuki "Okappa" Okamoto, who is usually calm but can turn violent. The trio means to get on with club work, yet they keep getting pulled into distractions, from fights between members to advice on confessing to a crush. Adapted from Kurii Cha's gag manga, the ONA runs as a set of very short comedy episodes with an ecchi streak, built around the girls' wacky conversations and increasingly outrageous situations.
