I can't think of a way to make that work in english either. Though it is funny that he got a hanamaru. Didn't know they did that in middle school.Tbh in the original text of that chapter, Tasuku said what I think was a wordplay with the word "花丸" ("hanamaru"), which is the name of that flower circle the teacher drew. It's like a gold star awarded to kids in school. I think he referred to himself with said wordplay in that panel.
I couldn't find a way to translate this to English correctly, so I replaced it with something that still conveyed the fact that he got rewarded/praised and went with it, and what Shia referenced on the last page of this chapter was that wordplay/nickname.
If you wanted to connect what she was talking about you could of had Shia say "Your teacher was impressed by your improvement in Japanese" or "you've even improved in Japanese" something along those lines to kind of make the link more explicit. Though pepole with the memory of goldfish like me probably would of missed it too.