After Satoru Watarai graduated from elementary school, he dropped out of school and decided to live within his apartment complex, never to venture outside. Satoru Watari then meets his old friends as they are coming back from their middle school classes. Satoru has now gotten a job at a cake shop within the apartment complex and eventually gets engaged to one of his friends. Satoru, still lives within the apartment complex only, but, as time passes, more of his friends leave ..

Set 10 years after "Kids Return." Shinji and Masaru have graduated from high school with different paths in their lives. Shinji attempted to become boxer and Masaru a yakuza. They both tried to rise to the top of their respective fields.

In 1944, the American military lands on the shores of Saipan. Refusing to commit suicide with his superiors or be forced into camps for prisoners of war, Captain Oba Sakae leads a group of his men and other similarly minded local residents into the mountains. Even after hearing reports of the Japanese military's surrender, Oba dismisses the reports as propaganda and continues to launch guerilla attacks against the American soldiers, earning him the nickname "The Fox". Soon, even the American commander who's charged with the task of capturing Oba comes to admire his persistent enemy.

Co-pilot Kazuhiro (Tanabe Seiichi) is up for promotion, but before he can get his captain's wings he has to get through a flight evaluation, and things aren't exactly going his way. He just crashed and burned on a simulated flight test, and his friendly examiner has been replaced with the tough-as-nails Harada (Tokito Saburo). On the same plane is cabin attendant Etsuko (Ayase Haruka) who's flying her first international flight and trying hard to not mess up. Elsewhere in the Happy Flight universe, staff are bustling back and forth with various problems and gripes - all to make this ordinary yet fateful flight a safe and happy one.

Godzilla saves Tokyo from a flying saucer that transforms into the beast Orga.