Monogatari no Sono Saki wa

"Senpai, clear this game for me!" Completely out of the blue, high schooler and game otaku Kengo is approached by a handsome junior, Miyuki. "What does an extrovert like him want with me?!" When Miyuki suddenly invites himself into Kengo's home, the older boy is on his guard. But despite being tall and incredibly attractive, Miyuki cries at horror games and is as friendly as a little puppy, and Kengo can't help gradually warming up to him. One day, Kengo discovers that Miyuki is actually an innocent virgin who doesn't even know how to masturbate!

(Source: Tokuma Shoten, translated)

Note: Includes an extra chapter.