I haven't done anything on trying to translate this, because I imagined Sayo would be all over it, and the conversation between Shirai and Oyajima is rather difficult. But there are a couple of places where some interesting kanji caught my eye. For example in the list of porn sites here:
Kodomo no Jikan 57 RAW Read Online
There is a description of each movie in Japanese before the
http://, and you nearly always see characters which I would translate as "moving picture"
動画 I don't know how to pronounce it because it isn't what is used for "movie" -- that would be "eiga" 映画 which refers to the reflective screen in a movie theater so it's not right for computer videos. Video is usually just spelled out ヴィデオ "bideo."
The character for "move" relates to a series of other kanji:
車 kuruma = car, we are looking down on a cart, the lines on the top and bottom are the wheels.
重 omoe = heavy, the car has gotten armored, with an extra line on top and bottom.
動 ugoki, literally "heavy sword" means "move" (as in moving picture)
働 hataru, to take it one step farther, is "person moving" and it means to work.
On this page, Shirai is teaching from the most basic set of Kanji
Kodomo no Jikan 57 RAW Read Online
EAR DOG
WOMAN ROCK FIRE
FLOWER FOOT
PS -- don't do this if you have delicate sensibilities but if you want to see what Rin has been watching, paste this into Google Image Search. Some pretty heavy stuff pops up. The first 2 characters are katakana, and they spell "ero" which is Japanese shorthand for "erotic." The last 2 characters are moving pictures, probably "do-ga"
エロ動画