If you're looking for manga similar to SPY x FAMILY, you might like these titles.
As leaders of their prestigious academy’s student council, Kaguya and Miyuki are the elite of the elite! But it’s lonely at the top… Luckily for them, they’ve fallen in love! There’s just one problem—they both have too much pride to admit it. And so begins the daily scheming to get the object of their affection to confess their romantic feelings first…Love is a war you win by losing.
Both are funny comedies.
Both have incredible plot settings.
Both are just fabulous.
Spy x Family and Love is War both have such wholesome banter and I love how overpowered the main couples are(in a good way~). Somehow the authors manage to blend two completely different people into a harmonious relationship based on the weirdest similarities. But, while there is a nice dynamic in each, personally I see a lot more human aspects in Spy x Family. They are both overpowered, sure, but they do have their moments that work really well with how the story progresses. This is much different from some of the many overpowered-mc-reborn-gets-revenge types, where the main girl is talked up as this boss bish but acts like an antisocial tween in order to be more "relatable." I dunno, that's just my opinion. Anyways yeah both manga are lighthearted and cute. :)
When calligrapher Sei "Seishuu" Handa becomes so enraged at a judge's critique of his work that he actually punches the old man, his father decides that Sei needs to reflect on his behavior and sends him to a remote island to live. Far from the modern conveniences of the city, the moody artist must adapt to his rural environment and his quirky but well-intentioned neighbors. How can he focus on his art when his appliances frequently don't work, his neighbors keep bothering him, and the neighborhood children have turned his house into a secret base?
This manga is reasonably new but has a lot of potential! The premise is that a spy needs to go undercover as a family man to get close to his new target and successfully finish his mission. This leads to him basically picking two randoms (that are more than what they seem) and the manga is focused on them all getting to know each other while keeping their past hidden from one another. Features a cute girl, a badass wife, and a diligent husband. It looks very promising for a lot of feel good moments!
In the day, Tista is a shy, introvert, church-going student whose ambition in life is to become a teacher. At night, she assassinates criminals as her alter-ego, Sister Militia. A special feature of her eyes give her the ability to spot a target from miles away, be it moving or stationary. Once she's spotted her target, it's one-shot one-kill. Why is Tista killing for the church? What happened to her father? How did she get those eyes?
Sengawa's day job is as an accountant working for the police. But at night, he transforms into a ruthless assassin bringing death to anyone who deserves it. Those who have been wronged and whose grievances the police can't - or won't - listen to, turn to The Man With A Thousand Guns to avenge their suffering.
Lou, Kei and Sonya are a popular trio of female singers who tour the country performing concerts and shows. However, the women have a secret - a deadly secret! The singing act is only a guise for their true profession - high-paid undercover assassins! Re-live the first adventures of the Pussycats as they take on dangerous missions against impossible odds...and have fun doing it!
On his right, his index finger on a trigger. On his left, a wedding ring. That is Tokichi's new life. A shy and clumsy salaryman, forced to become a hitman overnight. A double life: bowing during the day and gunfighting at night. He also has to juggle the two women in his life: his domineering wife and the jealous girlfriend he has inherited as his secret persona.
GO TO HELL!! Join Yukito Yoji, professional assassin, on his conquest to rid Japan of its many scumbags! Corrupt politicians, evil doctors, selfish moneylenders...no one is safe in this over-the-top violence extravaganza!!