In Shingeki radio for May 27th, REVO the songwriter for Shingeki no Kyojin’s OP wrote a letter to radio hosts Kaji Yuki (Eren Jaeger), Shimono Hiro (Conny Springer), and guest Ishikawa Yui (Mikasa Ackerman) telling them to sing the opening song. If they did it well, he’ll appear as a guest on the radio too.

So they did. xD

Add-on edit: The German in the beginning they obviously couldn’t say because they don’t know German! They have not heard the full song, only the TV version that we also know. Here is the first time they saw the actual lyrics, which they were rather surprised about. Also, the German part came with a Japanese translation which they learned for the first time means “Are you guys prey? No, we’re hunters.”

Considering all of this, they did rather well. :)

Sorry for this edit: For the Germans, before they get all up my ass about this.

Further edit, it’s like a train wreck: Onsen’s webpage took down this radio temporarily because the “letter from REVO” was not actually written by him. The staff also did not check with REVO beforehand that it was okay to play this song to the public. The radio is back up again after much apologizing from the staff, and this time with REVO’s permission. It’s unclear for now though if REVO will appear in the radio as a guest as the letter promised.