Koi wa Sekai Seifuku no Ato de

Both stories are in reference to Romeo and Juliet but in different methods. Both have characters fighting for opposite factions who fall in love and intrude on each other's daily lives and slowly introduce each support character as their relationship develops.  

Good vs. Evil, Angels vs. Devils, two comedies that are quite gag-like with high school students as MC's that fight each other due to their opposite factions but fall in love with each other amidst all the action whilst each episode passing, they grow more and more closer to each other. 

Spiritual Successor to My Dress Up Darling. Desumi and Marin are both blonde girly girls who are into wearing skimpy costumes and blushing a lot when spending time with the boy they like. And Fudou is basically Gojou with a Red Ranger/Gym bro re skin. 

Both shows are comedies involving superheroes and an evil organization where the focus is on something other than good vs. evil as a typical mainstream tokusatsu show is generally about. Both shows take a silly approach to drive up the humor and are creative in the way it's presented. 

Both involve two people who are natural enemies: one on the side of good and the other being a demon girl. They're supposed to fight but they quickly turn from enemies to friends (lovers in the case of Love After World Domination) cause the one on the side of good doesn't want to fight the one on the side of evil. Not to mention Fudo and Momo are both gym freaks. The general feel is more of SOL and the main plot is a bit secondary because they focus more on wholesome stuff in their relationship and develop the side characters. 

Both are satirical takes on a Power Rangers-like setting, but this is less drama and more romcom with a villain and a ranger being in love. 

Coming from Yoru no Yatterman: A heartwarming potential "what if" of Leopard's hypothetical future, if given a few years to grow up, then went back into the world and fell in love. If you finished Yatterman nights, you know you need it and you deserve it. Coming from Koi wa Sekai Seifuku no Ato de: Just like Desumi, while Leopard is plagued by the trope-code and dress code of villainy, she is still fully humanized and 1000% a protagonist one can empathize with. 

It's also about a daily life in a sentai-like world (the power rangers type of univers). It's a pastiche of the sentai genre. But "Koi wa Sekai Seifuku no Ato de" is more a comedy romance and "Mr. Villain's Day Off" a slice of life 

Cute and chaotic romance between strong and somewhat overworked long haired person and clueless and kinda dump but very lovable short haired person.  

if you are looking for another anime that basically has the Romeo and Juliet theme around it, like this one has, then Nisekoi is a great pick, although the way the romance flows is different. In Nisekoi you can enjoy more character development, it's a bit more serious, but it still remains an enjoyable rom-com. 

Red ranger of a Sentai team falls in love with a woman from the villain's side but each take different approaches: Shinesman has Shinesman Red fall in love with Shiina, the villain's cousin, while both are in civilian clothes, not knowing that the other is the enemy. Koiseka has a Red Gelato fall for the villain's top fighter, Desumi, on the battlefield. Both maintain a relationship while pretending to be enemies in front of their comrades.  

Both stories are based on the Romeo and Juliet narrative. Gundam: The 08th MS Team it's 'Romeo and Juliet with Mechas'. The boy is a Mecha pilot of the army that defends the Earth... and the girl is a soldier from the faction of humans who live in space that attack Earth. They will face an impossible love. (It is a spin-off of the Gundam saga but being an independent story it is not especially necessary to watch any other anime of that franchise)  

SSSS.Gridman was the first of the recent trend of tokusatsu - inspired anime. There are differences: Love After World Domination is a romcom parody where SSSS.Gridman plays it straight and they also do different tokusatsu genres (World Domination = Power Rangers where Gridman = Voltron) but it is safe to say that had Gridman not succeeded we wouldn't have gotten this one or Miss Kuroitsu from the Monster Development Department. 

Both share a similar sense of humor - irreverent parody of old action shows - and are consistently funny. Both have OP main characters. The main differences are their secondary genres: One Punch Man has cool fight scenes, while Love After World Domination has a cute romance and is ecchi-er. One Punch Man has prettier animation, but I find the animation quality of LAWD to work well with its humor. 

Both of them are about enemies who falles in love with eachother and they are almost the strongest soldier in the army.