Hoshii Seika♀

Seika is Izana's best female friend and more than a little bit prickly toward anyone who approaches her with ulterior motives (and because of Izana's easy manner and physical beauty, that is pretty common. She was raised by a strict father who sees her only as a convenient object to augment his own ambitions for the family line, which is a lot of the reason why she is so prickly in general. Her sole point of softness is Izana, whom she would probably do anything for.

[Edited from Fuwanovel]