Titular pictures of the characters can be found in 136-139.
The thin man from 136 is the father of the black haired girl from 139,
and the fat man from 138 is the father of the brunette from 137.

If you look at the group scene at the end (119-121), the girls are smiling when it's their own father inside of them.

Base +5, Tokizo +6, KaTIOWa +6, sashell +15

(18禁ゲームCG) [110415] [レッドレーベル] JK交姦～そこのアナタ、娘の処女を貰ってください～

Base +6, KaTIOWa +6

speculum P9
electric shocks P82-92

Base +10