Isekai no Seikishi Monogatari

A 15-year-old boy named Kenshi Masaki has voluntarily left his home on Earth to travel to the fictional planet of Geminar. The Sacred Mechanoids, humanoid exoskeletal weapons that were initially found in ancient ruins and refined over millennia, are used by the nations of Geminar to fight their battles. He is caught after deciding not to kill Lashara Earth XXVIII, the youthful ruler of the Shtrayu Empire, after being duped into taking part in an effort to assassinate her by a secret organization. Lashara decides to take Kenshi under her wing because she has learned enough about him to be intrigued by him and because his powers make him a very valuable asset. Asserting the identity of her attendant, Kenshi journeys to the Holy Land with her and her guardian Chiaia Flann. The Holy Land is a fortress that is practically impregnable and acts as a school for Sacred Mechanoid pilots (Mechamasters), the majority of whom are female. With his generosity, grit, and abilities ranging from carpentry and cooking to sophisticated survival techniques, Kenshi gradually rises to fame in the academy and wins the admiration of numerous female students, which causes some of the male students to feel jealous. A global struggle is about to start, though, as the same organization that tricked Kenshi is secretly operating inside and against the academy.