I was reading the first text of Tobira's chapter 7 and I am not sure if I understand this segment:
昔は日本でも、マンガは子供のためのものとと思われていたが、手塚はそれを小説や映画と同じような物語の表現方法の一つとして確立し。。。
My problem is with the latter part. I think it is saying this: "Tezuka established the manga as one of the ways of expressing stories like those of movies and novels".
Is it right? Is the それを referring to manga?
Your interpretation is correct. 確立する is a transitive verb that takes a direct object. As you said, それを refers to manga: In the past, even in Japan, manga was thought to be for children, but Tezuka etablished it as a way of expressing stories, similar to novels and movies...
Here's a few other examples
ルネサンスは人間の尊厳を確立した。 The Renaissance established the dignity of man.
保安官は、その町の秩序を確立した。 The sheriff established order in the town.
See: Transitive and Intransitive Verbs
And: Particle を
