Angels of Death
殺戮の天使 (original)
Most girls waking up without any memory and meeting a serial killer would panic, but not Rachel. In fact, far from being her biggest problem, killer Zack might just prove a convenient resource when it comes to finding a way out of the building in which they're both trapped!
Starring Nobuhiko Okamoto, Haruka Chisuga, Hochu Otsuka, Mariya Ise, Natsumi Fujiwara, Takahiro Sakurai
Watch "Angels of Death" on Crunchy Roll released in 2018. It's a animation and action & adventure show, and has a rating of 6.5 out of 10 from Imdb which is usually fine for this kind of show, and is currently available to watch for free.