Nanami in jail in Kyaro

[anokosa]

If you leave Nanami, she'll turn up later in Muse, when you try to get through the gate before going to the sindar ruins. And yes, someone takes her place in your party.

[ninjaluc79]

I hate Nanami
haha.
To me she just took up a slot in my party.
She wasnt that strong.
Couldnt use runes that well (Im a big big BIG rune user)
so when she "died" i wasnt that sad.
but it was ok to see her come back at the end.
But if i had my way id pimp smack her at the end like "BITCH YOU PUT ME THROUGH ALL THAT GREIF?!!?!"

It's not true for all GS2 files, I believe.
Nanami actually deserves a slot in your party IMO beacuse though she's not that good of a rune user, she's faster than most of the characters in the game. She's even faster than Riou, and can smack up to five enemies in one turn (Clive is better though; he can attack the whole hoarde of monsters in one turn). Put a support rune on her so she can at least do something to reduce the pain bosses inflict even before they can kill you. Add a Spark rune so that even uber-slow characters can dish out damage before enemies can kill them. Even Luca Blight will cower in fear at the sight of speed stars.

[Pesmerga VS. Yuber]

That thing with the Spark rune is the best, and I do it all the time, and when Nanami "dies" I use Spark on Sid, and equip him with wing ornaments.

[Magic Malcolm]

Anyway I should try to leave Nanami... But wouldn't that leave me with an emtpy slot or does a recrutee join instead when the fort burns down?

If you leave Nanami in Kyaro, you'll only have five party members going to Muse after the fort burns down. Once you get to Muse, Nanami will automatically take the sixth spot.

If you recruit Mukumuku in Kyaro, he turns up with Nanami at Muse too. Mukumuku will also join the party at that point, meaning you will have to lose one of the other three characters that came with you to Muse.