does the other guys appear as a couple in other manga of the same author? just wondering

Yeah it’s called shitsukekata = nijiuumaru

Actually, this manga is the spin-off of shinobu and daisuke's story (which I love!): http://www.mangago.zone/read-manga/shitsukekata_nijuumaru/
There is also another spin-off with the chieff's story:
http://www.mangago.zone/read-manga/boku_no_osekkai_darling/