According to this post, the studio was considering of using a female Sensei for the anime before a male Sensei was used instead.

And of course they went with the objectively worse design.
Seriously, just using the outfit from this version would've already been a vast improvement.

fsnfanboy said:

According to this post, the studio was considering of using a female Sensei for the anime before a male Sensei was used instead.

Well, that's a downer...