アージュマニアックス ～伊隅四姉妹最期の日～

One day protagonist meets with four sisters, who due to certain events starts living in his house. But he has to go to Europe to follow a story, and they decide to go together with him. They make reservations in an old castle which had reports of a princess' ghost, a legendary wolf, a lake monster and a crashed UFO surrounding it. And this is not even the beginning of the events to unfold around the sisters ... [Translated From Getchu] A crossover between multiple age works released in 2000.