Kaneda Miku♀

Miku is Haruka's younger sister. She starts out looking at our protagonist as an older brother, and as such doesn't hesitate to be playful with him. Of course, Miku eventually develops a bit of a crush on him, but keeps it to herself out of respect for her sister. For the most part, she acts like a representative of her sister, making sure that Hidenori remains faithful to her while waiting for the day when the blockade will come down.

[From Moroboshi Yuumei's review]