I think

I think the story was meant to be short. About how a guy is on his search for his Eros, the god of something, also known as Cupid. Maybe while on a mission or something he met that dude who he was enemies with and later on they became friends, seeing how it transitioned to black hair dude pointing a gun at the other dude to the other dude mending the wound of the black hair dude. Anyway, the whole plot probably revolves around finding your Eros and it seems like the other dude is starting to develop feelings for the black hair dude. I like this types of manga, it really makes you think your own plot and stuff