@boag considering the next chapter is titled "Hide and Seek" you know that's exactly what will happen. Because simply not opening the door wouldn't work. Mizuhara will hide, he'll open the door for god knows what reason, she'll espy Chizuhara's shoes that she took off and start looking around for her.
Also what's this idiocy about the Locksmith being closed. I've literally never heard of a locksmith that wasn't available 24/7, and it's not like there would be only one option to call. And why doesn't she have her landlord's phone number? "I knocked, no answer, guess I'll give up trying to contact them!" What kind of apartment complex landlord doesn't have a 24-hour emergency maintenance line to have an employee come out and let people in who were locked out?