User blog comment:Crimson and Darkness/DxD Updates 2~/@comment-2208155-20180330111328

DxD 0 will be about Sirzech and Grayfia first meeting

https://www.reddit.com/r/HighschoolDxD/comments/885xbt/dxd_0_will_be_about_sirzech_and_grayfia_first/

https://twitter.com/ishibumi_ddd/status/979485324127518720?s=19