Hayate and Kusanagi are best friends. They are pretty popular in their high school, and they always attract a lot of "unwanted" attention because of the ambiguous attitude that Kusanagi harbours sometimes torward Hayate. Invited both to a students counsel's sponsored meeting about UFOs, they stumble upon Hayate's little brother, Tatsumi. Hayate gets into an argument with him because he thinks Tatsumi shouldn't be there. And Hayate didn't know ho much he was right, when, after the meeting started: a UFO crashes nearby the student group...

(from B-U)