Ahnenerbe is a shop with two entrances located beside a cinema, and it exists in multiple locations, often appearing and disappearing. It also appears as a regular shop within different series, such as in Fate, where it is located near the large bridge in Fuyuki City. There is a rumor that people who under normal circumstances cannot meet each other are able to meet inside. It is the frontier where the worlds of Tsukihime and Kara no Kyoukai meet. Shiki Tohno and Shiki Ryougi, and Arcueid Brunestud and Touko Aozaki, are all related people that cannot be inserted together in a formal time axis without causing inconsistencies in the workings of either world. When characters from different works meet in this shop, any time discrepancies are eliminated so that they can appear at the age that t