A Nebutori's Tale by Seeker9043

Something strange is happening to your sister; she sleeps nearly all day, eats quite a bit, and can't seem to keep her libido in check. The most alarming is that she is gaining weight at a terrifying rate, already nearly immobile from her insatiable desires. Concerned your sister has been cursed you prepare to investigate the strange occurrence in hopes you can reverse it before it goes any further.
However caution must be upheld, for what ever happened to her may end up coming to you as well...