The girl was not only his Childhood friend, and practically the only friend his age from the Orphanage. (Everyone from their Orphanage has the family name Bruce) So his dream job that he worked super hard for was crushed, and then that same day he was rejected the girl who planned to have a relationship with him announced she decided the day prior to become one of Jian's mistresses. So yeah, the girl was a huge part of it, but basically every dream the guy had died that day.
We are missing the weird bit where somehow the knowledge to make Ballistic weapons are gone/lost to the majority. Also the area of space they are in now has so much bs in it that both long range communications and lasers are worthless.
This manga is going at breakneck speeds. The 'chapters' aren't very long, but we went through like 4 chapters in 4 pages. The Maria bit takes most of 2 chapters, and allowed more infodumps. Also pretty sure whatever declaration here doesn't really have someone overhear it if it existed. Makes me a bit worried since we are speeding through other slow bits when most of the first volume is the slow bits.
We are also missing quite a bit of Nao's internal dialogue, which tells us that while he is a death seeker, he will do everything he can to prevent other people from dying to his wish. Hence why he keeps thinking about captain's going down with their ship or heroic last stands, like Gandalf preventing the Balrog from chasing the group. Which is why him being thrown into any officer capacity is terrible for his dream.