I sounds familiar. Does the MC form a team with some countrymen and goes to some kind of sacred country were he fights against teams from other countries? And there was a team that looked like the Mafia.
mc does form team with his countrymen ( japs ) with the obligatory deliquent turned ally , smart guy , group girl , etc chars not sure about the sacred country part
also , in the office lady + bald swordsman + ??+?? versus mc and co. fight , one of the mc's comrades got seriously injured annd they were thouroughly beaten , till the mc started plot armor mode and went full retard on the enemy and , .......... got his ass handed to him once again on a silver platter