She is a former student of Rena Nakano (the Nakano Quintuplets' mother) during her 2nd year of senior high school and she is currently a cram school lecturer. She is first seen encountering Itsuki Nakano while visiting the Nakano Family Grave.

Spoiler

Shimoda exchange contact address with Itsuki and promise to keep in touch. Later, Itsuki is seen working part-time job with Shimoda.