Tsuyoshi Fujitaka 
My Instant Death Ability Is So Overpowered, No One in This Other World Stands a Chance Against Me! After Story [EPUB ebook] 

Now that they’ve successfully made it back home safe and sound, Yogiri, Tomochika, and the surviving members of their class begin the long work of readjusting to life in their own world. But even with their story finished, countless mysteries remain to be explored! This collection of short stories answers all sorts of questions left unanswered by the main series. What was Hanakawa’s previous adventure like? Who is Haruto Ootori, and why does he have wings? Just what has (the real) Enju been up to since we last saw her in the underground facility? There are plenty of answers to be found in over ten stories…and maybe another mystery or two to ponder!