Eren doesn't like water.
He doesn't like fish, boats, everything that has something to do with the ocean. When he's told to stay with Levi for a month, he practically lives beside the sea. And has a boat.
Eren gets himself sick after biology class after accidentally drinking two blood types: human and fish. He throws up several times, stomach cramps and headaches, sore and stiff limbs and sniffly colds. But all of that is leading to something. Something to do with marine life.
And that's about to change Eren's life completely.