A compilation of short stories:

1. Training
   This is a short colored one-shot. The older sister treats her younger brother like a dog.

2-4. A Sexual Molester
This short story starts out with a kid riding on the train to school. As usual, the train is packed and he is rubbing up against a woman in front of him. Painfully aware that he is getting hard, he rushes off the train only to be stopped by the woman who then forces him into a restroom and accuses him of groping. She then makes him pay for his actions by using him like a piece of meat. He eventually becomes her (and her boss') sex slave.

5. The Aunt
   Tsuyoshi's aunt, Azuma, loves to come over to his house and touch him in inappropriate places. On the outside, he puts up a front that he doesn't like it but deep down he actually does. One day when his aunt comes over, he tells her to stay in the living room while he goes to his room to study. Realizing that he has a massive erection just from looking at his aunt, he tries to relieve himself but is caught by his aunt, of course.

6. I Don't Like Cigarettes
   Rokujo finds a pack of cigarettes on the ground and notices that they're the same kind that his mother likes. As he puts one of them in his mouth to taste, he is caught by his PE Instructor, Kurokawa-sensei. Afraid that she'll tell his parents that he smokes, he offers to accept any punishment. Kurokawa-sensei obviously takes advantage of this... (This one-shot has a sequel in Ero Ane)

7. Lascivious Liar
   Kazuyoshi's sister is staying home today because she is feeling ill. Wanting to be a good brother, he brings her breakfast before heading off to school. As he starts to leave, his sister asks him to check her temperature by touching foreheads. As he leans in, his sister tazes him. When Kazuyoshi regains consciousness, he realizes that he is tied up. I am sure you can imagine what happens from there...

• Taken from BakaBT