Invaders of the Rokujouma!?

Someday, With Them... (1x11)

:

Kiriha invites Koutarou to an amusement park that she had been to before. Sanae and the other trails the couple as they spot a rhinoceros beetle hero show. Ruth disappears and wacky highjinks ensue. Kirito and Koutarou get on a Ferris wheel, where Koutarou hears the true purpose of her invasion and the story of her first love, but then earth starts to rumble...