Region Free is confirmed.

Korean Film Review
To Sir, with Love (Seuseungeui Eunhye) is a pretty entertaining horror, torture porn from Korea. As with many Korean horror films, there is a twist. The PQ from Taiwan distributor, BitWel is once again likely a DVD upscale. However what is very strange is that the movie clip that plays during the menu is true high def. That means that

1. BitWel must have had access to a high def master during this Blu-ray production and
2. There exists a true high def video master of this film.

So why is it then, the feature film is upscaled DVD rather than true high def? Who is responsible for this screwup/error?

Video: 1080p24 AVC encoded 1.85:1 (DVD upscale quality)
Audio: Korean LPCM 5.1 or DD 5.1
Subtitles: Optional traditional or simplified Chinese, Korean
Extras: Trailer for Say Yes

Try

dvd.jsdvd.com

it's region free.
NT$299 = US$9.0