This short story's about Kusumi, a college students, who accidentally hits Kijima (sensei) with his bicycle. Kijima hurts his right hand, but instead of suing Kusimi for money, he lets Kusumi work for him as his sort of secretary so that he (Kusumi) could write down the dictations of sensei. The reason sensei doesn't use any app or even a computer to do this work is because he's an old fashioned guy. Kusumi, of course, is more than willing to help because of the guilt that he feels (and because he's thankful he doesn't have to shill out any money).
And let's just address the elephant in the room first - the writer of this manga is obviously a massive Attack on Titan fan, because Kusmi looks like a taller version of Levi, while Kijima is what Jean would be if he were a bumbling mess. So now that's out of the way, let me get back to my review.
The plot is a little slow in the beginning, but it soon picks up. I really liked the depth that sensei's character is shown to have (even though it may appear otherwise), and how Kusumi's feelings towards him keep increasing gradually. All in all, I liked how their 'relationship' was treated without making the manga into a hardcore yaoi. That was hands down the best part about it.
Basically, if you're looking for something short and sweet, I'd recommend this manga. It's a solid 8 on 10.