Neil was the guy who kept badgering and imposing himself on Ren back when she was still living in the forest. It all started when Ren took pity on Neil's little sister and their mother who was suffering from an illness, the first of many instances of the gag of Ren getting involved in some small way only to get dragged into a much bigger spotlight.
She had to leave the forest due to his interference, only for him to show up and continue to harass her in Harula too, the town she went to next.
Beck or I guess Vector, is another person in Neil's party. He's seemingly the only sane and mature person in there who thought they were wrong to keep bothering Ren. The others are Neil himself who obviously has a crush on Ren and thinks she needs him, his oblivious other sister who sees nothing wrong with their conduct, and another girl who is Neil's self-proclaimed girlfriend and hates Ren as a result.
One wonders why Vector was in such a party then. He does seem to be the party leader/mentor...but I don't get what keeps him attracted to stay wit them.