Translation of the full talk Manami gave to 11 year old Kirino.
I see. But you know, Kirino-chan.
I think liking onii-chan in that way is strange. I think it's not normal. I think it's weird. I think a lot of people will be disgusted at it.
Obviously, siblings won't be able to marry, both of your parents will certainly object to that.
The more serious Kirino-chan's feelings are, the more older you'll get without changing, the more unhappy someone will become.
It can't be helped, someone certainly will, for example, Kyou-chan, nothing you can do about it.
Not only the present Kyou-chan, but the one you liked in the past too.
Because you see, Kirino-chan, that "cool onii-chan" that you admired didn't even exist.
That's why, Kirino-chan.
You must not tell anyone about those feelings.
Hurry up and forget them, give it up, reconcile with your real onii-chan and become normal siblings!