Narue no Sekai ED - Ice Cream (by Chiba Saeko) played perfectly for me. As for the song I liked it a lot, very nice.
It get´s 8/10 from me.
And here´s one of my absolutely favourite OP´s.
"Forever" by Savage Genius from Erementar Gerad or Elemental Gelade.
(I´ve actually had this song, and only this song, the full version though, on repeat for two full days straight.
)