[I-Raf-you (Various)] Microne Magazine Vol. 68 Koko ga Nengu no Osame Toki desu

A towering older sister with a curvaceous, bountiful figure greets her tiny younger brother with an eager declaration that "this is when we offer New Year's money," her dripping excitement barely contained as she looms over the classroom. Their playful dynamic quickly spirals from innocent sibling wrestling into something far more twisted, as she pins him down and boasts of her victory before her body swells into an impossibly massive, naked form that dwarfs him completely. The brother gapes at the overwhelming scale of her voluptuous frame, stammering in shock at how enormous she's become while she gleefully anticipates getting even closer to him.