Teenage boy Masato Oosuki was chosen to beta test a new MMORPG, where you're actually teleported inside the world of the game. But once he gets there, he finds his mother has followed him, and she's incredibly strong, too.

Mamako and Masato are now registered as hero and mommy, and they decide to have an interview to decide who’ll join their party.

Wise joins the party as they prepare to visit the village of Maman on a special quest that Shirase gave them. But first they have to buy equipment, and Mamako is overjoyed at the idea of going shopping with her son.

The "Empress of Night" turns out to be none other than Wise's mother, who she split up with after a fight. When the two of them went their separate ways, the Empress decided to stop playing the game and instead go chasing after attractive men.

To thank the group for all their hard work in the past, Shirase invites the party to enjoy the sunny beach. While enjoying the wonderful weather and pristine waters, an accident causes Masato to lose all his memories, including those of Mamako!