TSUBANA

Two schoolgirls, Kane and Takagi, are friends who (mostly) enjoy their everyday life together. However, in their world, crazy stuff out of fantasy and sci-fi is common and accepted. For instance, Kane's nuclear-shelter-bedroom is useful for hiding out when an unknown menace starts destroying houses. Also, the girls often try out new fad technology like face-hiding necklaces or elaborate meal flavored gum. They might even be found using a computer to go hang out with a friend in the afterlife. It seems like anything could be possible in their world! 

There is a phenomenon where the young who have their hearts broken completely disappear. The protagonist is Hime Ayaka who is the most popular girl in school. As such, she is a frequent target for confessions. She has turned down everyone who has confessed to her and caused them to disappear. Yet, there is seemingly no end to the boys eager to shoot their shot. With the boys thinning in number and the ordeal putting Ayaka under stress, her friends come up with a ludicrous plan to put an end to the confessions.