The main character is your seemingly typical anime guy in high school that listens to music and has a bunch of perverted thoughts about girls all the time, but who turns out to be quite different than your usual main character guy and he has a crush on this girl that he sees on the train all the time and he ends up taking a picture of her and putting it in his phone. In class, another girl who he happens to sit next to, named Sekai, sees the picture in his phone and tells him her name and then, from there goes about getting him and the girl on the train to know each other so that they can try and start a relationship, all the while falling for him herself.
This anime is very much a psychological anime and deals with relationships and what happens when someone cheats on someone, but not only one person, many people. The main character is one of the most despicable characters I have ever seen, if not my MOST HATED character and cares nothing for the people around him, it seems, but to be able to hate him that much and to have so much passion for his pain and wishing something bad would happen to him was an exciting feeling because I really felt he would have to get what was coming to him. He hurts basically every single person he meets and cares nothing about how they feel when he is done with them, only to use them again in the future. He walks all over every girl in the anime, save one or two, and they all basically sit around begging for more mainly because they want to know what it's like and why the others are doing it, so they do it, too.
The majority of the anime the main character is, in my opinion, a sociopath, as well as a sex-addict, but there are moments here and there where you see that his actions actually do bother him and these are very important in this particular anime because if they did not have them, he would truly seem to be a monster. It is sometimes scary that the most evil people are not demons or supernatural at all.
The ending is something that is perfect, though, in my opinion and it is something I ABSOLUTELY saw coming, but the way that it was done was really something creepy and gave me chills - I really enjoyed it! It was an awesome turn, but something I saw coming the entire time and something I kept repeating throughout the entire thing, over and over again and when it finally happened, I was extremely happy and satisfied. It has a very twisted ending, as well, so do not be fooled by the innocence of the title because this anime is anything but innocent, but make sure you watch until the end because there is more than just one awesome, sick twist at the end that will leave you satisfied with the feeling you get watching the rest of the anime.
Everyone basically gets what they deserve because this anime shows that the human mind and heart is an extremely fragile thing and that you can't just push someone aside like they are trash the second you are done with them because they may not be done with you or ready to let you leave.
