Emi is a character in Daily Lives Of High School Boys that appears in episode 9
Emi first makes her appearance in High School Boys and Drop Kicks, where she kicks Hidenori into the river, thinking it's Kiyohiko. She is then thrown into the river when Hidenori pushes them into the water.
In High School Boys and the End of Summer, it is revealed that she and Kiyohiko have spent more time with Hidenori enjoying the summer together. During this she has developed feelings for Hidenori, but she is sad that he would be leaving the next day. On the final night together, she sends Kiyohiko off in order to tell Hidenori how she feels about him. Before she can confess her feelings though, Hidenori reveals that they are actually cousins to which she is mortified.