Minase Yuuma

The protagonist is a pleasant young man who is finally getting used to life as a member of society, but he is so desperate to get used to his new life as a member of society that he forgets to enjoy himself. In addition, he wasn't that much of an outdoorsman to begin with, so he just lazes around the house on his days off, and finally has so much time on his hands that he wonders what he's doing; but in the end, he's too heavy-handed to take any action.
However, just as he starts to seriously want to change his current desiccated life, his junior, Natsuho, slaps his butt while saying "go get yourself a girlfriend!", and then he becomes a little more proactive.