Train_Man: Densha Otoko

It's about an Otaku guy who fell in love with this beautiful lady and tries his best to get that girl with a lot of help from 2channelers (people who goes/posts on 2ch). This story has become very famous in Japan and I believe they now have novels, several series of Manga (both Shoujo and Shounen), movie, drama, play, etc, etc.

Perpetual geek, social basket case and obsessive fan – needless to say, the guy called "Train Man" has never had a girlfriend. Most of his days are spent immersed in electronics and waiting for the box set DVD of his favorite anime series. But fate takes a turn for Train one ordinary night on an ordinary train ride. He falls in love at first sight with Hermess, a gorgeous fellow passenger. When a drunken rider tries to harass her, Train surprises himself by coming to her rescue. But when Hermess later contacts Train with a thank you give and the possibility of further contact, that's one situation he can't handle. He immediately goes online to a popular chat room to solicit advice. To his horror, he's encouraged to ask her out. Soon he is bombarded with advice regarding how, when and where he should do it. Will Train Man find true love, or will all this pressure to come out of his shell be too much for him to take? (Source: CMX)

Geeky fanboy Ikumi Saiki has a dream that someday, somehow, he'll finally get a girlfriend. Then one day, on the train home, he rescues a beautiful girl from a troublesome drunk. Now the girl sees the hero inside the otaku -- and it appears that Ikumi will finally find romance! But though Ikumi found the courage to save her, will he ever be brave enough to win her heart? Desparate, Ikumi posts an urgent plea on an Internet message board: "Help me with the girl of my dreams!" Ikumi's story ignites the whole online world. Everyone is ready to help Ikumi prove that even an otaku can find true love! (Source: Del Rey)