Is This A So Called "Isekai"? - Our Greatest Days

In an alternative universe the author of this story dies.

Yet in this universe, isekais can actually happen, and he soon gets transported to have a brand new life in an universe of his choice, a crossover one is chosen in the end so he can finally meet his beloved.

But along the way, many adventures, both everyday and dangerous ones comes along. To put it simply; One heck of an isekai adventure awaits.

(Remake of "Is This A So Called 'Isekai'?", focusing on having the two arcs build up much more for the third arc, including some other major changes and additions to the story.)