Seina Yamada might be the unlucklyest or luckest boy in all the universe. He's married to four beauitful women, and today just happens to be his 18th birthday. Seina still commands the Kamidake II and does jobs for the GP as a "decoy". Because Seina was 15 when he was married, all the money he made at his job went to his four wives, and to Seina's family back on Earth. Today, Seina turned 18. Which allowed him access to his vast fortune he made with the GP. Seina, Ryoko, Kiriko and Amane hasn't settled down on a planet yet (although Lady Seto had suggested him he should stay on Jurai more than once).
Amane wanted to give Seina a birthday to remember. Seina's birthday party was at the GP Acamedy. It looked like the population of the Acamedy was going to the party wheater they were invited or not.
Amane belonged to a race that evolved from snakes, much like First Class Detectives Kiyone and Mihoshi. So she could swallow people whole and alive, but had problems digesting live food. Anyway, Amane wanted to eat Seina for her birthday present. She told nobody about her plan, because Kiriko would go through the roof and Ryoko would raise hell. Amane would get Seina all alone when she ate him. She had wanted to eat Seina for a long time, but decided against it. The GP frowned on eating your superior officer...or by eating anyone else for that matter. But that wasn't going to stop Amane from eating her lover.