User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-2405:204:9697:11D5:39C4:2589:6D24:F6BC-20180422164326/@comment-172.222.66.26-20180423165438

Ishibumi said in the afterword that this is an alternate universe version of Mitsuya, so it's likely not the same universe.