Hi! There's only a few things I remember about this novel. It had mecha, military schools, and I think the MC either had dreams of the future or reborn as himself (aka died then woke up in the past) or something? The MC is naive and cheerful and the typical Gary Sue type. I'm pretty sure it was abo since the MC had to give up his dreams when he was a kid to be a mecha designer cuz of sexism but then chose to pursue it anyways when he was in high school/college. The MC came from a reputable family and had a grandpa who was a good mecha designer. The MC was also the captain of the cheer team at his school. I also remember there was a competition between 4 military schools, and the leaders also decided to add a fifth school to the competition (the MC's school). No one took them seriously in the beginning since the MC's school was "known" to be the consort school, a place where people look to for a good spouse.