The only thing that's putting me off aside from the difference of Koito is her friend and the teacher. SIS WAS IN ELEMENTARY SCHOOL WHAT A FUCKING PEDOPHILIA TEACHER. The age gap is too large and I found it really hard to even read the parts and the characters not get alarmed because even a MIDDLE SCHOOL x teacher relationship is off-putting. I personally like reading age gap romance stories, but the lowest I'm comfortable with is first year of high school. Aside from that, this is pretty okay so far.
Boku No Orion