Tsunashima Erika♀

Erika is an old friend of Takashi and his wife. In fact she has known them for so long that they think of her as their little sister. She has just returned from studying abroad. Erika was always a bit childish and pampered, but it seems that her trip abroad has helped her to grow up a bit. She's a very cheerful and happy girl. However, she's also hurting on the inside because of her unrequited feelings for Takashi. When she met Takuya, who looks a lot like Takashi, she became more than a little interested in him.

[Edited from Ben Woodhouse's Walkthrough and JAST USA]