That time... Is insane, by the way. World record/top runners are around 5.5 seconds, and I think great runners can get to 6.5 with training. He's at around a 7.3 as a middle schooler...
Joking aside, this manga is so wholesome. (there are ofc, some dark undertones especially in the beginning). For all crap that people give about some characters, they're still kids. And we can see that they're growing up a bit. I would honestly want to see a high school arc just to see how they all panned out.