A summary of season one of Tensei shitara Slime Datta Ken with some extra content leading into season two.

Once upon a time, the demon lord Rchimedes spread terror throughout the world, until he was eventually sealed away by the legendary hero Creasion. Since then, a thousand years have passed peacefully. However, a mysterious hole has opened up between the demon and human spheres, and countless demons have surged into the human realm once more. Coming to the conclusion that Rchimedes would soon return to wreak havoc, a human king summons the possible descendants of the legendary hero—all 75 of them. Unfortunately, after so long, it was too difficult to pinpoint his true descendants. Among the lionhearted prospects is the amateur adventurer Alba Frühling. His skills may not be top-notch, but he is accompanied by the talented soldier Ross, who helps the young hero whenever he is in a pinch...or at least, he is supposed to. Though undoubtedly a skilled warrior, Ross is actually both sarcastic and sadistic, and hence revels in Alba's suffering. Senyuu. is a comedic adventure following the unlikely duo as they struggle in their endeavor to defeat the demon lord, meeting various eccentrics along the way. [Written by MAL Rewrite]

Tomoya Aki, Megumi Katou, Eriri Spencer Sawamura, Utaha Kasumigaoka and Tomoya's cousin Michiru Hyoudou (all members of a doujin circle called Blessing Software) go out location scouting for their project, a video game. As Eriri attempts to get Megumi to act out a scenario for the main heroine, Utaha lures Tomoya away and forces him to act out a romantic scenario with her. (Source: Wikipedia)

Austral Island is located 2,000 km south from Samoa islands. The existence of the island was removed from the official records, and Tagami Yuu made a journey to search for the reason. He sailed for the island with Dr. Waive who was his father's friend, Doris who is the daughter of Dr. Waive, and Captain who is the friend of Dr. Waive. On their way to the island, GAIL, the international conglomerate, and gangster, Cougar Connection lead by Lady Lynx attacked them. They managed to arrive at the island, but suddenly a mysterious monster began to attack them. When they became ready for death, a blue giant robot appeared. It destroyed the monster and saved them. Although it was an existence far beyond human knowledge, it reminded Yuu of something warm and familiar. It was Giant Gorg which is called "Messenger of the God" by the inhabitants of the island. Escaping from the attack of GAIL's assault team, Gorg guided Yuu into the underworld. There, he found alien's relic and an alien who woke up after 30,000 years' sleep. (Source: AnimeNfo)