Without a single boyfriend in sixteen years, Natsume has zero relationship experience … and it’s all thanks to her super overprotective neighbor—high school teacher, Mikami-sensei!! Whether at home or at school, Natsume is always being manipulated by his strangely overbearing affections. But while it may have seemed like sibling love at first, their relationship soon takes an unexpected turn … !
Natsume and Mikami-sensei are boyfriend and girlfriend in secret. Wanting to enjoy lovey-dovey days with Natsume, Mikami-sensei refused to become a general manager for his dad's company and made an outrageous declaration: "I'll become a high school student!!" No one could have expected that Mikami-sensei would become a high school student in the name of love! And so, a rowdy high school life that involves even Shiro-kun and the other two Mikami brothers begins?