You were exiting your room when you spotted a suspicious man with a white bouquet. He is standing at your neighbor's apartment's door. Her name is Hoshino Ai, a housewife with a cute twins who started living here not long ago. But this man is definitely not her husband. As you're walking pass, Ai opened the door. You saw a gleaming white of a knife under the bouquet. "Congrats on your dome concert." He said as he prepares his knife.

Whatever will you do, it's now or never.