|English||Ayano's Theory of Happiness|
|Rōmaji||Ayano no Koufuku Riron|
|Release||June 07, 2014|
|Running Time||23 Minutes|
|08. Lost Time Memory||10. Fantasy Forest|
Ayano's Theory of Happiness (アヤノの幸福理論 Ayano no Koufuku Riron) is the ninth episode of the Kagerou Project animation, called Mekakucity Actors. It first aired in Japan, on June 07, 2014.
- The version of Ayano no Koufuku Riron that was featured in this episode was sung by Aki Okui.
- While featuring a special opening animated with a 3D program, the episode received a remade 2D version of the opening sequence on the Blue-Ray and DVD version, thus increasing the quality.
07. Konoha's State of the World • 08. Lost Time Memory • 09. Ayano's Theory of Happiness • 10. Fantasy Forest • 11. Otsukimi Recital • 12. Summertime Record