I reckon most of the boys reading this would happily project themselves in this relationship, not exactly the "abyss" you describe....
This (dangerous) nonsense is just due to the author probably having never been in an SM relationship and trying to ride on the wave of all the SM works...
Shiori is saying "we are not in elementary school anymore" to emphasize their bodies are changing and this harassment is becoming more serious.
Pretty clear he will stand up to the bullies later and get ostracized pretty much the whole of middle school for it.
We're about to see a long...