The world is in chaos. Before you knew it, your world turned upside down. You went from being a normal student to a zombie killer. No one knows how or why this infection started, but you can only survive.

You escaped the Academy with your best friend Takashi and your girlfriend Rei, forming a group with Takagi, Saeko, Shizuka, and Hirano. You've been through so much together that you're barely able to process it all.

You recently escaped your last refuge before it was overrun by "them." You arrived at a casino that was still relatively undamaged. It's quite well preserved; in short, it has about 10 floors, with several rooms, a hotel, and other luxurious amenities.

It was a great discovery, but they couldn't be entirely sure. Before resting, they thoroughly investigated a large part of it, blocking every possible entrance and leaving only emergency exits. They blocked the main entrance with several casino tables and machines so none of them could get in, and the windows were boarded up with thick planks

Each of us chose a room, but at Rei's request, she chose to share a room with you.

The room is luxurious, it must be for premium guests; it has a large king-size bed, a chandelier, a spacious bathroom with a bathtub that can be turned into a jacuzzi, a flat-screen TV, and room service... which, for obvious reasons, is no longer available.

You're currently lying in bed, wearing only your boxers, when Rei emerges from the bathroom, dressed only in orange lace lingerie. Luckily, you managed to find a clothing store before arriving there; you assume that's what she grabbed. It really accentuated her appearance, giving her a refined, elegant, mature, and sexy aura, especially her breasts and buttocks.

"Ah~, how I missed a good hot shower." She says with satisfaction, finishing drying her hair and throwing a towel onto a nearby armchair. She slowly slips into bed, her breasts bouncing as she does so. "Hmmm... Thanks for keeping the bed warm." She says with a smile.

Outside, it's raining. It's already night, and the rain is pouring down rapidly and relentlessly, raindrops crashing against the ground. It's accompanied by the thunderous sound of thunder and wind. Such noise silences the world, so that nothing else can be heard, in a way, giving the world a veil of privacy. Inside any building, nothing could be heard, everything shrouded in mystery.

It was summer; during the day it was around 28° to 30° Celsius, so with the rain came a cool wind, a sharp drop in temperature, and a cold that penetrated many barriers. Attacking the heat, lowering everything to around 1° or 0°.