'Itsuka mata aimasu ka?'.
再び
mou ichido itte kudasai.
As in 'see you later?' You may say 'jaa, [mata] ne.'
Japanese would say sashiburi
Yurei wo Miteita!
see Google Translate
Miru koto wa dekimasen
You may say 'Eiko ni aitai.'
ja ne mata ne
urigami nakoruto hertforumenas
'Ima watashi wa mieru'.
Because they are happy too see you again if they really like you!