There is an anime, "Ef: A Fairy Tale of the Two", which puts in evidence a think that I would not expect. Am I right on this one?

The anime narrates the story between two couples. My point: the boy of the 1st couple, Hiro, when he was a child, encountered two sisters, Kei (with which he will have a platonic relationship) and Chihiro, (the girl of the 2nd couple). He stayed overtime with them. Hiro likes drawing, and passes time with Chihiro. One day, Chihiro goes out to buy some mangas, and Kei asks Hiro to go to the beach. Hiro accepts, and Chihiro returns, she discovers where they are, and pursues them. But in the meantime, she has an accident, and lose her left eye and has problems of amnesia.

(for the japanese audiences)アニメの 2 つのカップルとの間の話をうかがうことができます。 私のポイントは、第 1 回カップルの男の子、ヒロ、彼が子供だったときに、 2 人の姉妹は、発生した Kei （と彼はプラトニックな関係があります ) 、千尋（第 2 カップルの女の子）。 彼は残業をしました。 ヒロの描画、同類のちひろ時間を渡します。 ある日、千尋一部のマンガを購入するが、圭とヒロは、ビーチに移動します。メッセージが表示されます。 ヒロを受け入れ、千と千尋を返し、彼女はそれらが、追求することを検出します。

The thing I don’t understand is that, on the anime, the blame is of Kei who asked Hiro to go out, but according to me the blame is of Hiro who accepted, because he had free will to decide, he wasn’t controlled by some magic power, possessed or something. Am I wrong?