Watching gameplays of Mouthwashing (video game by Wrong Organ)had made me emotionally attached to the characters except for Jimmy ( the one who's about to get hit by an axe from the illustration). The characters are well written and so is the storytelling, the thing about Mouthwashing's structure of storytelling is that it is told in a series of flashbacks and jumping back to the present moment.
From these illustrations, most drawn is Daisuke ( the guy with the pink Hawaiian shirt) he is a very relatable character. This character is probably in his early twenties and is being pressured by his mother to be useful and find a job and that's the reason why he ended up in Pony Express. Being forced into an internship that he never wanted but decided to put on a brave face so his mother could feel proud of him one day.
Among the characters he is the youngest, in the game you can see him trying to be helpful and trying to fit in among his crewmates. He tries to be optimistic even in a dreadful situation when their space freighter provided by pony express has crashed into an asteroid, that's why Swansea (the one with the axe ) calls him a "useless, ray of sunshine".
These collection of illustrations are just a fan made scenario of their interactions.