Haven't seen Kongou yet in this series but if this Hiei is like any other, then there definitely wouldn't be any need to worry.

That 130% affection level fake-British girl would be disposed already in this base

Hiei might not be after the admiral, but the opposite might be true!

coz Hiei is a bro

She is such a good bro that I love her

is this Kirishima protecting her little sister?

I doubt it, more for the fact that they don't see her as a threat because her intentions aren't romantic.

Tsuchino said:

is this Kirishima protecting her little sister?

Kirishima is the youngest bro