I can already tell what sort of doujinshi she wrote after coming up with this plan.
"So Mai, what subject are you worse at?"
"Well uh... I missed sex ed. so, I guess that..."
Yikes, Japan don't play around. A suspension over here is simply "you don't come to school until further notice" - a temporary expulsion essentially.
We do have something similar to this called 'isolation', but it's still nowhere near this level. It's essentially a normal school day but you...