Hitsuji to Okami no Koi to Satsujin (2019)

Kagami Tsutako has been obsessed with Ii Azami for 20 years. While stalking him one day, she encounters Ii Azami being hit by a car. When she discovers he has lost his memory as a result of the accident, she decides to claim they are lovers in order to fulfil her lifelong desire. As a result, as Tsutako repeatedly lies one after another they begin to increasingly escalate…

Both dramas deal about a girl in college that has a tendency to kill people, who did bad things. And in both dramas she meets a guy that helps her and knows about her tendencies. Both are very similarish with how the girl works and who helps her.

Romance n crime involving serial killing.
Reason maybe different but both female leads are in habit of killing. They both r serial killer.
The romance in both is deep n guys love them despite them being a killer.

“There are women who inspire you with the desire to conquer them and to take your pleasure of them;
but this one fills you only with the desire to die slowly beneath her gaze.” _Baudelaire

Similarities between the two:

-Suspenseful horror Love Kome.
-Unconventional romance of a sheep and wolf couple.
-Symbiosis of a dysfunctional and abnormal pair.
-ML has near death experience due to strangulation.
-FL is a killer and the ML is under her tight grasp.
-Crazy, traumatized and morally tainted leads.
-Complex, ambiguous and twisted relationship dynamics.

Sakuragi Shun is a salesman who works for a Sunbath Home Housing, a house manufacturing company. He enjoys a happy life at home with his wife and daughter. Due to a sudden personnel change, he was assigned to transfer to Kagoshima, a city he was familiar with from his junior high school days. There, for the first time in 17 years, he is reunited with his first love Takeda Hana. She works as a junior high school teacher, while her husband who works as first mate, spends most of the year at sea, so she usually lives alone. While reminiscing the bittersweet memories of their high school days together, a hidden Pandora's box begins to open...

Furthermore, sparks also fly with Katoyama Naoya, Shun's friend and former love rival from their junior high school days, who now works for another company in the same industry. Although Shun has a beloved wife, the flames of jealousy quietly flare up. Meanwhile, Sakuragi Shun's wife is trying to suppress her anxiety. Based on their phone calls and emails, she becomes suspicious that her husband is cheating on her, and in order to eliminate her fears, she takes a trip to visit him in Kagoshima. As the slight lies begin to pile up, the truth becomes complicated, and when the lies are exposed, how will the relationship between the four of them
change?

They're not exactly the same, but there's a hint of similarity. It's just this movie is like a thousand times more hardcore than He Won't Kill, She Won't Die and the roles are reversed. Watched the latter first, and really liked the concept. If you're open to "weird/strange" movies, then these two will fit your palate.