Trinity Seven manga volume 13 features story by Kenji Saito and art by Akinari Nao.

It's a face-off between Luxuria masters as Lilith and Anna battle it out! There's only room for one of them in Trinity Seven--who will reign supreme? In the world of Demise, Arin and Hijiri partner up on an important quest--rescuing Arata! He's sleeping deep within the halls of the Terminus Library. Will the power of true love be able to wake him from his slumber...?