Gamer's Girlfriend summary:
A Japanese high schooler gets a part-time gig at an arcade, where he’s pretty much ignored by everyone–people even start calling him an “NPC” because of the way he blends into the background. All that changes when the gorgeous, larger-than-life Yaegashi Nanora barges into the place and demands his help learning the ins and outs of the arcade’s trickiest games. It isn’t long before she suggests they start going out, beginning a summer full of arcade fun and simmering sexual tension!