Animation & Sound - 7/8
The animation here is nothing you haven't seen before, but pretty good either way. Most importantly, attention is paid to the private parts and the appropriate amount of detail is added. To me this sets this show a couple notches above your standard hentai that simply draws a slit and a few squiggles and then calls it a day.
The music is fairly simple but well done. There is minimal background music but this allows for the sound effects and the voice acting to shine. The sound effects are great in all their sloppy and gooey glory, but I was amazed at the quality in voice talent here. Granted a hentai isn't the best showcase for up and coming (no pun intended) talent, but the male lead here really got into his role. Sometimes it's the small things like this that can make a show immensely more enjoyable.
Character - 7
I found the protagonist in this show to be the best of his kind that I've seen so far. He took all the hallmarks of a great lecherous chikan and combined them with a legitimate backstory and human element. This man had a purpose and you could feel it from his gaze and voice. His chikan smirk and sideways glance were second to none.
The 'victims' here are yesterdays villains and take the form of a lawyer, young girl, doting elder sister, and the somewhat spicy middle sister who dislikes how the youngest is constantly doted upon, but still cares for her in her own way. These characters gave a pretty nice variety and served their roles in the show well.
Story - 8
The chikan elements of this show and the revenge plot by themselves are pretty standard fare, but the combination the two provided was something I haven't seen before. While many hentai only proffer enough plot to get the sex started, Hissatsu Chikan Nin turned this approach on it's head and used sex as the method to tell the story. While many other chikan shows involve molestation as the end point in a character's journey, here it was used as a means to accomplish a goal only. Once the objective was accomplished, Koichi gave his heartfelt thanks to his chikan sensei and then gave the impression that he would proceed with his life. This ending scene made me LOL on one hand but on the other it was a very well done and powerful scene.
Enjoyment - 10
This was a fantastic show and the best train chikan hentai I've seen thus far. Using train molestation as atonement for a wrongdoing is a bit different from the standard degradation and also different from the "women ride trains because they want to be molested" line that many shows seem to take. I wholeheartedly recommend this show not only to chikan enthusiasts, but to anyone looking for a great hentai with a fairly legitimate plot.
