it focuses on their friendship/brotherhood with adventures so his character has bonding like what you said but it's not only with the other male lead, literally the other males too because they were friends.
bromance don't mean literal romance between the two males. It's brotherhood/ friendship. Anyone can add that tag in MDL. I think that was added because of the BL fiasco in the comments there and has misunderstood that the guys will have romantic feelings with each other. Both of them there has their own FLs btw.
Boy's Love - has romantic feelings with each other (same sex)
Bromance- platonic friendship/brotherhood.