it has a cake who's a detective

Thought about an idea for a shoujo with a "dark" twist to it a while back - the plot starts out cliché and following some of the generic tropes commonly seen throughout shoujo works; MC is a young girl who falls for her childhood friend. Everything is uguu and doki doki for many years until a sudden timeskip - they're both grown now, happily married and living together (no children, MC is unable to have any - sad cliché's are necessary). She's working a generic office job while her husband works as a homicide detective.

All that happy, lovey-dovey atmosphere starts to die down with time. Both are too busy working to even spend time with each other. MC can't even enjoy a nice night's sleep with her husband since his job basically has him almost living in his office, and the sudden increase in what appears to be a string of bizarre serial murders isn't helping.

MC really starts feeling the isolation now - coming home to a dark, empty room and hearing the sound of her husband's automated voicemail message became the normal. Some days he'd manage to come home and get a few hours sleep before suddenly being woken up by calls urging him to get at the scene of a crime. MC doesn't even shiver anymore at the loss of warmth when her husband leaves her side.

The murders started increasing. Then one day: her husband didn't come back. She assumed he was staying over at the office, it happened a lot, so she let it slide. Then the next day passed - a call that she eagerly picked up and answered in a sing-song voice at the thought of it being her husband immediately turned into stunned silence as she was greeted by an officer who told her they needed to inform her of something regarding her husband.

Turns out he was missing, and the only remnants left behind were his bloodied coat - which they assumed might be tied in to the copious amount of killings going on. MC can't help but let out a chilling cry, the statements from other officers and investigators promising to find him fading into the background.

Another timeskip, because why the fuck not. 3 year later and MC wakes up alone; brushes her teeth, does her hair, opens the closet - grabbing her usual business clothes and sliding it aside to reveal a police uniform. Next scene is her at the police department, knocking on the chief's door before stepping in and standing before his desk where he was busy writing papers away.

She cuts to the chase quick - reminds him of how many years she has been working on the force and how she wants to be promoted as a homicide investigator. He accepts, knowing how well of a loyal officer she is and that the unit was in need of more investigators - especially since those murders were still going on, and they didn't even have a single firm suspect as of yet.

So she becomes a detective, starts becoming close with the other members of the unit who were once friends with her husband, investigates case after case of those murders that all seem to tie in together -and in the conclusion of that, she finally puts in the last pieces of the puzzle. Though, the culprit behind it all wasn't who she expected: her husband. Turns out it was him all along. Completely shocked to find out that he is still alive and the murderer, she can't help but freeze when it comes to pulling the trigger on him. All the uguu shoujo moments they had start flashing in her mind as he tells her that they'll meet again before vanishing once more.

She immediately lets it be known to the other investigators that her husband was the one responsible to the unsolved cases - and she's met with nothing but concern. No one seems to believe her; they all seemed to just accept the fact that he was probably just dead and had his body well hidden considering his position - as a sort of taunting warning to the other detectives.

Lots of other things happen, and by the end of the series, she managed to convince a good portion of the investigators that suspecting her husband wasn't such an impossible theory. They set up a plan to ambush him, but she resisted against this and said that he would only ever show himself to her. They face down, he confesses to everything and lets her be known of the web of lies he had her trapped in; how simple it is for love to blind someone from picking up the truth - all the little bits that, had she paid attention to, would have caused her to see there was something "off" with him.

She shoots him, and being in agony over it all and feeling pathetic for letting herself be carried away by love, knowing that she could have prevented many of these deaths if she had just picked up the signs - she turns the gun on herself, and the screen goes to black.