Mangas

ゲーマーズヘブン!
Buyer beware - when video game obsessed Kaito Suzuki mysteriously receives a game called Gamerz Heaven, he gets a lot more than what he bargained for! Not only is he playing the game, he finds himself being sucked into it! With a boy named Nata serving as his "Navigator" in the game, Kaito will have to eliminate all of the monsters before he can enter the Second Zone. Things become difficult when Kaito realizes that losing this game had deadly implications for the real world!
グラビテーション
Shuichi Shindou is determined to take his band Bad Luck to the top of the Japanese pop charts. With his drive, talent, and satiny singing voice, he just might stand a chance. But Fate throws a wrench into his well-oiled machine in the form of a handsome stranger named Yuki, a romance writer with an attitude. Yuki is Shuichi's biggest critic, but as the two young artists gravitate towards each other, friendship, and perhaps something more, is sure to blossom.
In order to heal the wounds in Eiri Yuki's heart, he and his vocalist lover, Shuichi, travel to New York to visit the grave of Yuki's first love and tormentor, Yuki Kitazawa. They discover that the first Yuki has left behind a young son, Riku, and so the odd couple takes the boy back with them to Japan. When Shuichi receives a kiss from nutty rival band leader, Ryuichi, Yuki flies into a jealous rage, and he and Riku disappear, leaving Shuuichi to search for them in vain.
キミのうなじに乾杯! -  キミのうなじに乾杯! -  乾杯! -  Cheers To Your Nape! -  Kanpai!
From ANN: What with humans killing, exorcising, and otherwise getting rid of them all the time, monsters and demons have become endangered species. Someone has to look out for them, and that's what Yamada Shintarou is training to do- he's going to become a monster guardian. Armed with a two-by-four and a talking rabbit, he goes out to fight the demon hunters, hoping to defeat enough of them to get his monster guardian license. It is while he is doing this that he meets Nao, a normal (if unusually pretty and violent) high school girl, and instantly falls in love... with her neck. Now Yamada has a new mission in life: to protect Nao, and keep anyone- monster, ghost, demon hunter, or otherwise- from getting in the way of his view of her nape.