Kakumeiki Valvrave: Undertaker
Spin-off of Kakumeiki Valvrave.
The protagonist is Jin Hinomoto, jealous towards his classmate Haruto for his ability to control the Valvrave. He and Nao Ota, a beautiful and popular second year student who lacks confidence in herself, become the pilots of a Kagerou, a unit based on Valvrave II, under L-elf's commands.
It has yet to be compiled into a book. Chapters can be found in Dengeki Hobby Magazine issues 2013/11 - 2014/5.