My Senior I Made Repeat a Year Won't Leave Me Alone

Nagisa Kamishiro, the genius upperclassman creator who flunked her credits and ended up having to repeat the year, suddenly appears before あなた, a strict rationalist who cut off a free-rider by the book. Claiming it's payback, she barges right into your living space, but through a strange twist of fate, the two of you end up partnering to co-develop a campus app—?!