The protagonist lives a lifestyle of nothing but playing video games which is why he's not very popular with girls, but it's also in a video game community where he met a girl who he kindly taught some strategies, which improved her skill at the game. She thanked him for his help, and they decided to meet offline and celebrate.

As he waited with his heart pounding, the person who showed up to meet him turned out to be a 211cm tall landmine girl. She is enormously tall but cute, and this girl continued to make his heart pound while they toasted in celebration, whereupon he had too much to drink and blacked out...

And then after regaining consciousness, upon looking at his surroundings it became apparent to him that they had just finished having sex...

The author who doesn't have a girlfriend, draws a situation that even a virgin would fantasize about at least once.

(Source: FANZA, translated)

Note: Released at Comiket 104, 105