Man... I hate when timelines don't make sense... Bleh.
Just to be clear about what I mean is that the referenced Valentine's Day chapter (chapter 9) from "last year" has Kazuma present calling Mikoto Senpai, meaning it has to be her second year. In chapter 30, it shows her class as 2-B, meaning she is a second year. Valentine's Day is before they change years, meaning it is a plot hole.
It doesn't matter to everyone, but it does to me. It was probably written because it was around White Day IRL, but nevertheless this will bug me.