Full Metal Panic!

Their new mission… is to peacefully raise a family!? *Full Metal* returns! A thrilling new series begins! "I'm going to need a weapon. They're in the closet. Go get them." 20 years after the climactic battle for the fate of the world, Sousuke Sagara is married to Kaname Chidori and they are living a peaceful life together. "Dad, you want your usual carbine and grenade?" "You're still hiding a stash!? Every time you say, 'I don't need weapons!'" "Mama, the enemy is coming. You can complain later." Their daughter Natsumi is a high school girl who matches her father's fighting prowess, and their son Yasuto, an elementary school boy, is a skilled hacker. Now that they have joined the family business, the word "peace" is no longer in their dictionary.......!? A brand new series depicting the exciting daily life of the Sagara family! (Source: Fantasia Bunko, translated)

A sergeant by the name of Sousuke Sagara is assigned an important task. That of guarding high school girl Chidori Kaname. Sousuke is a military genius, gaining high rank at an early age, but because of his strange upbringing, he lacks social skill. Now, he finds himself as a fish out of water as he attempts to protect a girl from an evil organization and turn in his school work on time. (Source: Anime News Network)

Tells the same story as Full Metal Panic Second Raid and is as such, also based on the novels The End Of Day By Day. Leaving off after the original series, this series tells of Sousuke and Mithril as they fight Amalgam. Like the original series, but both sides have gotten a bit more aggressive...

Tetsuro Kasahara manga adaptation of Shouji Gatou eponymous novel. *Note: This adaptation interrupted publication after a disagreement between the original novel author and the artist of the manga version over Gatou's disparaging comments of Swedish environmental activist Greta Thunberg, leading Kasahara to claim he will no longer promote Full Metal Panic! Zero nor draw any continuation, and will instead donate any profits from the manga to environmental groups.*

Sagara Sousuke isn't your typical high school student. He reads military enthusiast magazines; he responds to questions with "affirmative;" he brings grenades to school in his bag. Though everyone at school takes him for a hopeless military geek, Chidori Kaname thinks there might be something more to him. When their plane is hijacked in the middle of a field trip, Kaname's instincts will prove correct: Sousuke is an elite, mech-piloting mercenary... and he's here to protect her! (Source: J-Novel Club)

1. Side Arms - A Sad (Tonal) Range, A faraway (Firing) Range サイドアームズ - 音程は哀しく、射程は遠く 2. Side Arms 2 - Voice From the North サイドアームズ２ - 極北からの声

Much akin to Full Metal Panic? Fumoffu, Overload is a series of seemingly random, silly, high school adventures of Sousuke and Chidori.

This is another story in the Full Metal Panic universe, set some years after the events with Sousuke and Kaname. Ichinose Tatsuya is a pretty normal high school boy, who lives with his father and little sister Yukari. He has a tendency to fall in love with foreign women, which has never turned out well for him. One day, while up in the mountains driving a Power Slave to help out with his father's company, he runs into yet another beautiful foreign woman, called Adelina. He lends her a hand and is surprised to see that she has a military Arm Slave, called "Shadow," with her. What is this mysterious and highly armed woman doing up in the mountains? Tatsuya's life is about to get a lot more exciting... (Source: AkatsukiUlquiora)