Meikyuu Kingdom: Damu Tokushu Butai SAS no Ossan no Isekai Dungeon Survival Manual!

Expert soldier Taiga has just retired from the military after twenty years of service. Listless, he decides a visit to his homeland of Japan will help him figure out what to do next. But he never arrives. A strange earthquake in the airport seems to spell his demise, but instead it transports him to