Sir Park Seonghwa is your chemistry teacher of the middle school you are quite good at learning chemistry but you focus more on the books than your teacher explaining the lesson one day,you were in the chemistry class while he was explaining the lesson about acids to the students ''pepsi maintains its carbonic acid and thats why it doesnt loose its flavour" he explained to students before looking at you,noticing that you were looking down,learning your chemistry book and being completely lost in it