A to F (Alpha Bitch, Bitch in Sheep's Clothing, Didn't Think This Through) | G to L (Gold Digger, Humiliation Conga) | M to R (Obnoxious In-Laws, Relationship Sabotage) | S to Z (Spoiled Brat, The Unfavorite, White-Collar Crime)
Whether the plan's goals involve stealing someone's love interest, planning a luxurious wedding, divorcing a poor spouse to remarry a Meal Ticket, or simply tying someone down to themselves with a pregnancy, the antagonist's inability or unwillingness to think before they act or examine the (sometimes obvious) flaws that their schemes may carry will often be the thing that causes their downfall. Therefore, this warrants MoniRobo a Didn't Think This Through subpage.
- "My sister tried to steal my fiancé…"
: Chieko and Taeko's mother quit her job immediately after the former told her she could move in once she got married to her fiancé, thinking it would happen. However, she pays for it when the man dumps Chieko for someone else. To make up for the loss, both women harass Taeko with demands to hand over her fiancé, Shinichi, to Chieko. This eventually escalated to the mother-daughter duo luring Shinichi to their house so that Chieko would win him over, but the man flees and reports it to Taeko. Moreover, when the mother called Taeko again, she pointed out that they could have asked her, but it was too late because of what they did. - "She abandoned me because my business wasn't going so well but...": Kanemi manipulated Oota, an introverted loser, into marrying her since his father was a wealthy real-estate tycoon. Moreover, Kanemi thought that even if they got divorced, she could still get half of his family's assets to spend on all the luxuries she could. However, Atsumu reveals that since she never worked and squandered Oota's money on frivolities, she will only be left with next to nothing as a divorced couple only has to split the assets they acquired during the time of their marriage, so Oota will keep all the assets he acquired before that. On top of that, she'll get even less money if she pays compensation. Eventually, she ends up destitute as she not only has to pay compensation to Oota for everything, but also has to pay compensation to her lovers' wives.
- "My little sister asked me to plan her wedding…": Reina has her older sister Nano slave away to plan a luxurious wedding and even agreed with the service providers to offer a discount. However, Rena changes her mind mid-planning and books it at a cheaper venue using Nano's plan document. Little did she know that said venue, while beautiful on the outside, was notorious for its piss-poor service, over which her fiancé, Yuuto, chews her out. Moreover, he learns that Reina tried to book a luxurious wedding for cheaper because she blew his budget money on host clubs. As a result, both he and Nano sue her for compensation, cancellation, and wedding fees at once. While Reina got a job as a hostess to pay the debts, she got fired and banned from host clubs because she was ignorant of the business' unspoken rules, leaving her completely destitute and at the mercy of loan sharks.
- "On the day of an important presentation, she tries to bring me down": After Nano won the presentation contest, Ayane Azato plotted to have her go to an alley under the pretense of retrieving important documents and then have a delinquent ambush her so she would give the presentation instead. However, the delinquent didn't foresee Nano holding on to her purse enough to let herself be dragged along it, causing him to hightail it out of there. Moreover, Ayane herself didn't know that things like these would attract Masayoshi's attention, and his prompt exposure of the crime she committed as well as the bullying she meted out on her juniors caused her downfall.
- "My friend who stole my fiancé two years ago tried to do the same thing again": Marie hijacks Ayako's relationship with Kenji and marries him as a result as he was wealthy. However, Marie ends up regretting it as she ends up moving with him to his mom's house, where she endures a life of emotional abuse rather than the rich celebrity life she expected. Moreover, when she gave birth to a baby boy and therefore an heir, the mother-son duo barred her from tending to it, which led to her running away.
- "The new recruit is using her family's powers to threaten me!": Ikari constantly used her status as a Mafia Princess to slack off and force her workload on Atsumu under death threats on him and his loved ones, despite the financial troubles her father's group went through being the reason Ikari worked there in the first place. However, she ends up paying for it when she pulls this on a Yakuza boss far more powerful than her father, who then exposes Ikari's abuse of power to her father, who didn't know about it.
- "My sister stole my boyfriend. But, at the end, she finds out the truth about him.": After stealing Kunihisa from her "ugly" sister Nobuko and marrying him, Atsuko thought she would live a rich celebrity lifestyle. Instead, she endured abuse as she found too late that Kunihisa was the leader of a misogynistic cult that forbade women from having luxurious goods and starting relationships with non-cultists. Eventually, her parents also joined the cult and spent themselves broke for its sake and Atsuko lost her sanity to the point of being hospitalized.
- "My sister looks down on me and even tries to steal my fiancé": Eriko plotted to seduce Tatsuma Ukigaya into dumping his fiancée, Kyoko, and remarrying her instead. The reason was that he beat her own husband, Masamitsu Asahara, in looks and wealth, and by taking such a catch away from her "ugly" sister, she thought of it as killing two birds with one stone. When it seemed to work and they went on a date at the MoniRobo Hotel, she didn't know that it was a set-up by both Tatsuma and Kyoko to have her confront Masamitsu for essentially having an affair. Moreover, she didn't take into account that Kyoko was the one who exposed her to Masamitsu, nor that the man would have signed a prenup to leave her with nothing in case of a divorce. In other words, she ended up ruining her own life in pursuit of more riches than she already had.
- "A mom friend stole my husband and disappeared.. 2 years after the divorce...": Two years after Mitsuya and Keiko ran away to have endless affairs, the latter ends up pregnant. With no money to have an abortion, Mitsuya decided to have the baby and then dump it on Masumi so she'll look after it and pay the debt he racked up. Needless to say, their plan fails when Masumi takes the baby to the hospital and turns the tote bag it went in as evidence to the police, which results in the lovebirds having their filthy apartment raided by the police and put in jail before being forced to Work Off the Debt.
- "My ex wife who disappeared was the bride at my best friend's wedding": Yuko cancelled her wedding with Shuichi and went on to marry his best friend, Takafumi, simply because the former only earned $1400 a month and the latter was a CEO's son. Moreover, she had Takafumi invite Shuichi to their wedding just to rub it in and shame him in front of the guests. However, they didn't foresee that by then the "poor man" had become successful and that he would acquire the groom's father's company. Therefore, such a display of irreverence caused Mr. Hirokazu, Takafumi's father, not to promote him until he took responsibility for his job. Furthermore, Yuko didn't consider that Mr. Hirokazu would run background checks on her, which allowed Takafumi to sue her for a large settlement after the divorce, which landed her into a grueling hard labor job under Mr. Hirokazu's watch.
- "My girlfriend cheated on me so I took the best revenge possible at our wedding…" features a rare case of the protagonist not thinking things through. When the Professor has her assistant, Psycho, equip a special app into Kakeru's phone that allows him to take "the best revenge possible". While such an app scares him, he uses it anyway to expose his cheating girlfriend, Aika, on their wedding day. However, he didn't foresee that the Professor would pull a Deadly Prank on the bride's lover, Hiroshi, and while Mr. Macchio saved the bastard right before getting impaled, the experience left him with a huge trauma. Moreover, he becomes horrified when it's implied his revenge got Hiroshi killed anyway, this time from Psycho dissecting and eating him.
- "My boyfriend got my subordinate pregnant...": Manami succeeded in baby-trapping Takuya and stealing him from his fiancée, Satsuki, and things went smoothly for the couple as Takuya himself paid compensation to Satsuki. However, she overlooked one flaw in her scheme that led to her downfall; the baby girl took less after Takuya as she grew up, which eventually drove him to perform a DNA test five years later. When the test results confirm he isn't the girl's father and that Manami drugged both his and Satsuki's beers so she could get her way, he divorces her, leaving her destitute and working at a shady shop while leaving her daughter at a daycare.
- "My little sister ruined the contracts I had with a client...": Miyuki plotted to steal Mizuna's fiancé, Riku, since he was the manager of Robo Robo Tradings. Her plan could have succeeded if it didn't involve raping the poor guy. Moreover, she was ignorant that Riku's father would intervene rather than stay put and let a strange woman force herself on his son. While this screwed MoniRobo Trading Company out of a contract with RRT, it also caused Miyuki's father to be fired from the company not only for enabling her rape of Riku but also for abuse of power and embezzlement. As a result, Miyuki's family ends up destitute as both she and her father have to pay compensation.
- 'My ex-wife took one of my kids with her saying "I'll give you the useless one!"': After Yoshiichi's company went bust, his wife Akane divorced him, took all his savings, and the custody of Mayuka to live off of her since the girl was good at academics unlike her twin sister Mayuko. Unbeknownst to Akane, Yoshiichi worked around his current situation and Mayuko became top of her class in both academics and sports. Moreover, Mayuka became a rebellious delinquent because of the neglectful treatment. She tries to "rectify" the issue by getting Yoshiichi to swap twins so she could live off of Mayuko instead. However, he has none of it and demands to take care of both twins, who promptly show up to chew Akane out before Yoshiichi called the cops on her for child abuse and neglect.
- "My wife cheated on me with her doctor…": Mana divorces Kengo and leaves him the custody of their three daughters, Reina, Nami, and Misaki, so she could remarry Dr. Nakajima and live off his money as he seemed willing to marry her. However, Mana finds out too late that not only is Nakajima a serial womanizer, but also married with a kid. When she returns to Kengo's house to get back with him, he has already exposed her affair to both his parents and in-laws. She then threatened his property to cow him into submission only to have the cops called on her when she fumbled on hitting Kengo. When she finally brought up the girls, the three of them chew Mana out for being a neglectful, cheating bitch before the cops took her away.
- "My wife cheated on me to make me jealous, and got pregnant…": Sari cheated on Kei with her ex-boyfriend, Yuto, to make the former jealous and thus "love" her again. Unsurprisingly, she becomes pregnant and despite her attempts to reassure Kei that the baby is his, he is understandably pissed off by her willingness to commit adultery under such a harebrained excuse and divorces her instead. As a result, she ends up remarrying Yuto and enduring Domestic Abuse from him.
- "My wife was cheating on me while she was on business trips…": Masami cheated on Ataru with his brother Yuusuke and plotted to divorce the former to remarry the latter since he was the golden child. However, she didn't account that while Yuusuke was "fun" to her liking, he was also too dimwitted not to lock his phone, which Ataru searches for evidence. Furthermore, he gathers both his parents and in-laws at the inn where she would have her latest affair, causing Yuusuke to be disowned. While she assured him that she would look after him since she was a working woman, she didn't know that Ataru also called her boss, who promptly fired her for embezzling company money and using its premises for her affairs.
