If you're looking for manga similar to Tenjin, you might like these titles.
Noemi Kohiyama is a second-year student at Count High School, a school with no established reputation in the world of tankery. Her first match as a tank commander is against Saunders University High School. She directs the crew of her tank with her orders, and she follows the orders of their team leader. At that time, she remembers the words that her senior said to her.
Yosora Fujimitsu is a newly admitted student to North Gate National Military Academy, a school where the elite gather. Yosora possesses both beauty and intelligence, but he immediately feels uneasy at his new school. He thinks, "At this school, there's some kind of big secret." A vortex of speculations occupies Yosora as he's led toward that secret.
Nadeshiko Otemachi’s entire family are killed in a terrorist attack… A few years later, she enters into a military school for the sake of protecting Neo Tokyo. In order to get out of an awkward situation though, Nadeshiko decides to join the S Class, a specialist course for the most elite students in the school. But the S Class, and its S rank members, isn't exactly what she expects.
Isami Kondou is a young man who has just started his university life studying at the National Defense Academy - an organization with the aim of training students to become high-ranking officials of the Japanese Self-Defense Force. During his overly-strict life at the JSDF academy, he experiences grueling times, and also happy and joyful times, all the while growing into adulthood. This is the youthful story of a young man conquering all obstacles that come his way!
Mysterious flying creatures known as Zai suddenly appear, and in order to fight the creatures, mankind creates fighter aircraft called "Daughters," as well as the automatic fighting mechanism "Anima," which are shaped like human girls. The story centers on a young man named Kei Narutani, who yearns to fly in the sky, and an Anima considered to be humanity's trump card, a girl named Gripen.